Wait a second... I think the presence of Hyper Training has a secondary implication as well:
Most of the previous generations have content for Pokémon up to level 70-80 or thereabout. For in-game purposes, there are very, very few reasons to train a Pokémon all the way to level 100 (those very, very few reasons being that some legendaries have level-up moves at level 100). In-game opponents therefore cap out at level 60-65, maybe a few daily trainers have 'mons at levels above 70, and some very, very powerful challenge trainers cross the 80 mark. With no reason to level up something to level 100, there's no efficient way to do it either. You may go to '100 if you want, but the road is long and there's little to gather at its end.
With Hyper Training, though, the games give an explicit reason for you to level up a Pokémon that far. It encourages trainers to walk the distance, and therefore it might provide a convenient way to do so as well. True, it's been a while since the games became an epic grind-fest from level 60 onwards or so (GSC and RSE, anyone?), but even in XY it takes a while to get to level 100. SuMo might raise the level bar again to avoid excessive grinding. Perhaps Game Freak even caves and gives us in-game opponents with 'mons at level 100, or at least above the 90 mark. I definitely wouldn't mind battles which give my top trained 'mons a bit of a challenge.
Another thing is the definite admission to everybody that IVs do exist, that some IVs combinations are plainly better than others, and that you're ideally looking for 31 across the board as a rule of thumb (Trick Room and such nonwithstanding). They have had fixed-IV giveaways of Pokémons in generations past already (the Ralts traded to you from Diantha in XY, for instance), so there's a possibility they'll just peg some giveaways 'mons and legendaries to 6x31 IVs already. Hyper Training is a measure to combat excessive grinding, re-setting and hours of discarding Pokémon in the hunt for something optimal. Might as well make the new shortcut as short as possible.
Lastly, if my Bottle Caps theory is correct - that there are different kinds of Bottle Caps with different degrees of usefulness - we might look forward to find a lot more stuff in trash cans, which I'm pretty sure I'm not the only person obsessively checking every time I find a new one. Even if it's nothing more than the Hyper Training equivalent of a Clever Wing, I'd be glad to see anything else than "the trash can is empty" in 95 % of all cases.