Community Manager Grimiku officially replied in the Blizzard forums which unveiled some interesting information about Diablo III Ultimate Edition. Read below:

We’re still working out all the details regarding if and how Ultimate Evil Edition will be supported post-launch (e.g. will we patch the game after it ships? if yes, should we only patch to fix bugs and address critical game issues, or should we patch in new content as well? at what frequency should we patch?), so we don’t have an answer for you right now. That said, I can confirm that UEE will ship on all platforms with all updates included up to patch 2.0.5, and that there will likely be a “Day 1” patch to add in patch 2.0.6 content, too.

As we move closer to ship and finalize our post-launch patching plans, we’ll be sure to keep you updated. Great question, though!

In short, Diablo III Ultimate Edition will undoubtedly receive required and critical updates, however, they’re unsure whether they’ll be adding extra stuff to the new patches or not. Diablo III Ultimate Edition has been confirmed to at least include up to  2.0.5.