Quick update (as I was asked offline) about where I am with Thrift 2. You may have seen HBASE-8818, which covers my efforts. I had help from a Thrift 2 user, Hamed, to get quite a few ticked off so far. I am now working on a few larger ones, namely porting the coalescent counters and the bounded thread pool support. I have those changes local and will up them for review once I am closer. I am AFK for a short while soon, so all in all I am expecting to get the remaining changes in within a month or two.
Seeing that before no one worked on this, and we even (if you ask me foolishly) proposed to drop Thrift 2 albeit having users of it, I think that is reasonable. It may not align with release cycles, though since I am not part of that I am not aware of what that could cause - please provide input here if you can.
Overall, Thrift 2 with the recent and coming additions is superseding Thrift 1 quickly, so I am strongly in favour to deprecate Thrift 1, either now for a 0.96 release, or when you think it suits. But Thrift 1 has effectively no maintainer (dedicated committer) and I am only going to work on Thrift 2 going forward. So that seem to be a clear path forward.
Any questions, please ask. Otherwise look out for more, larger patches to trickle in over the next few months. I will get there for sure. :)