If I were running Sprint that will be last out of the box with the 6.5 upgrade, I'd definitely want to do something to make it special. But since Sprint is running Sprint, I suppose its users can expect an old build with no improvements to Touchflo, or perhaps no ROM update at all.
In fact, knowing Sprint, who knows. Maybe it will decide not to release any updates just to spite the users who really want it and have been begging for it. You know, sort of how Sprint made news a couple years ago by "firing" users it thought complained too much. Sort of resembles Congress' attitude towards the American people, actually.
If it's the same Sprint I fired a few years ago, I wouldn't doubt it. If they do release the update, they'll be doing it begrudgingly.