Perhaps it's the foremost goal now for most people, not to be a runaway success, but to situate yourself so you get a comfy-enough seat in which to watch how it all unravels. It's been 13 years, and it seem the point of the reunion is to strip away whatever attenuations becoming visibly adult after high school brings upon you -- something for self-esteem purposes you need to feel you'd donned -- to mostly lounge back, lifelong, into a niche, a "knit," you've always known as pleasing and comfortable. Well, for these characters -- good for them. It'd be nice to see people settle into their permanent habitat after they're fully formed rather than while shadows of greater essences -- of true world-exploring adventurers, of truly individuated, mature couples; but I think even with where they remain they'll have fun, know some good living.
I think they'd be wise, though, not to be made subjects for any further films. Stifler, the only one of them who remains an agent of true living -- that is, not just a joiner in common-place activities like horking down hotdogs with genial-enough friends, but generating, initiating upon them new adventures, experiences and landscapes -- seems pretty much near used up by film's end, exhausted from having to play through all the requisite and predictable (note: in a time where collectively to help bide time we make ourselves feel evolved and accomplished perhaps primarily by ridiculing white male alphas, it plays out as requisite, not a surprise, that his high school sports-mates are all gay) humiliations that have to be suffered upon him.
The film seems to realize as much, as an effort -- a sustained one -- is made to resuscitate him in the last few moments before the finish. All of a sudden after so much victimizing he's generously funnelled every plausible available target to feast and food for himself through thorough banging or deflating -- without of course -- or at least done in a fashion that gives ready avenue for denial -- chisseling away one iota at categories of people we are fully vested in remaining righteously affiliated with -- some renewal and vitality. But it still plays out with him seeming more like their potentially straying, thoroughly wrought-over, hyper-respondant traumatized dog than a co-equal who can confirm with what he generates that yet still with ample provisions, mapped-out destinations, and of course, pre-selected accomodations, they'll know in life some subsequent true adventure.