It's been suggested before, but it can't be that far off.
While the alignment may never go away, it seems no less likely that college do away almost completely with the second back. Per Chris Brown of Smartfootball.com:
"almost every good team is one-back based (even option teams)." That, naturally, takes the fullback off the field most of the time. In place, various moving parts are manipulatable to pull safeties out of the box, pull an extra DB on the field, or pull a LB into space, giving so many more options than simply having a fullback behind the QB or moving around inside the tackle box.
Brown's focus is almost exclusively college, sadly, but it's fantastic - and he recently put out a book, The Essential Smart Football. Go get it. But, in the last decade, college has outinnovated pro, starting with the Bears' explosion (and regression) with Gary Crowton but more notably teams like the Patriots and Saints taking the antiquated Erhardt-Perkins scheme (think Jeff Davidson) and using spread techniques to modernize it - and then, of course the Wildcat and option additions. It hasn't come with much of a pro counterpart in coaches that will employ it - that's still mostly a failure, and pro-style coaches are the few that seem to get hired (I believe that the better way is to innovate in college, and become a pro assistant). But, college does most of the innovation offensively, and of course, defensively to counter it.
And college is where athletes become position players. If you have your backs, and you have guy you can develop into a fast, 240 lb player, that's more likely to be a LB now than a FB you will barely use. They're not going to have a fullback who might play five snaps backing a more talented RB, and then ten snaps playing FB for that RB who works better in space.
Or, if hands are good enough, that player becomes a smaller TE they can move around, spread things wider so they can take defenses deeper.
In the 70s and 80s, pass offenses in the pros adjusted and used a lot of split backs. It saw its zenith with the early WCO, and the utility FB became a big piece of that, too. Of course, that's died down, and it became harder to play run concepts from split backs, without the positives in the passing game continuing.
With spread and one-back comes a much easier application of zone blocking, which is almost a universal concept in college and pro now. Add in that spread, and non-spread teams alike, are using more shotgun. Shotgun takes away a fullback, or lessens the need; if you did have a second back with the QB, does it matter if it's a RB, FB, TE? And which of those three is less versatile? For that matter, lacking a top fullback much of the year, but having two good TEs, of course the versatile Coryell offense here turned to the TE as a makeshift fullback, most of the time Greg Olson just to highlight that blocking wasn't the first concern.
To that end, TEs are just more versatile than FBs - taller, more able to fill either role, more likely a matchup problem in space. An ideal blocking fullback is more bowling ball than receiver, and the most prolific receiving fullbacks (Larry Senters, Richie Anderson) were less able to do much else, as well as not being that matchup guy. They were just open men most times. Any player who has that ideal level of blocking, strength, athleticism, and versatility to play TE or RB would be at those other positions, almost every time, instead. There are no weapons of the level of Graham or Gronkowski.
You could say that play action will die a quick death - and probably not. You can still use motion, and a handoff fake to the RB, to sell. Certainly, you don't need an I-formation, TE Right set to run playaction anymore than you need it to run - you run playaction off of your run plays, so if you're not I-Form to run, and you want your runs to be less easy to read, you are more set for one-back. Zone blocking even deceives the defense less. But as Bill Walsh once said, "if you really want play action, you pull a guard." You don't need a fullback to pull a guard, obviously. And Walsh was a common advocate of getting a lot of your passing done on first down - shorten the chains - which lessens the reliability of requiring a first/second down "base" offense or defense. Things haven't worked that way for years.
To go back to the Pats' example for instance, their use of backs in general has been bizarre but specifically that needed lead blocker - they've used defensive linemen and linebackers often the last few years, likely more than any other team. They had a fullback, Heath Evans, for a while but he wasn't that good a blocker either. Now, of course, here in Carolina there's Mike Tolbert. The squatty fullback will play the position, sure. But it seems a placeholder, waiting a year to see what happens with Jonathan Stewart. And Tolbert's value is getting another pair of hands on the field, not as much his ability to ram his body into a body to move it. Which, given the way of the NFL, may become a lost art for player safety anyway - LBs and FBs have to have it tougher longterm than linemen.
But, Carolina did so much of its good work without a fullback anyway - with Newton in shotgun so much, and the option being the only time I can specifically remember a fullback making a difference. It's difficult to find a lot of time in the past that a fullback has been integral to a team - maybe LeRon McClain, who's more runner than blocker; maybe Vonta Leach in Houston, but Leach became quickly expendable because Arian Foster just does so well with the one-back zone read. The alignment will be there, the look will endure, but I just don't see it becoming a major part of a team's attack anymore.
At best, for most teams, it's a change-up, and while it's never something that's going to be 'gone', and I don't think we'll ever see all teams go 1980s run and shoot, it's also hard to see the already-disappearing fullback be a big part.