So I finally had some time to play around with 3.6 beta, and I made some discoveries regarding Ice Climbers:
As documented, the momentum bug was fixed, however, I've also discovered some undocumented changes (PMDT Pls).
The ability to control Nana's throw direction, and therefore, perform infinite handoffs on any character was removed, and Nana will now always throw toward the ledge, or U-throw based on stage position.
Nana no longer uses Up-B for recovery when She isn't close enough to grab the ledge. This change is a positive, as it makes saving Nana generally easier for the ICs player.
This is all I've found so far, but if I discover any more changes I'll share them.
Basically, No more infinite, but the momentum bug has been removed and the Nana AI is slightly better at recovering. I would say this is a slight nerf to the character in terms of strength, but a step in the right direction for the character's design.