Though I'm not expecting any meaningful update, I may email the SimUniqueLab owner to see if he has any updates on MSFS. The bad thing is, even if he does, and even if he shockingly does a surprise release, I suspect that non-Russian audience would be out of luck in terms of purchasing it for the foreseeable future. 

For completeness while acknowledging this is skewing outside of the original ask, on the wider "Soviet/Russian/Eastern Bloc" aircraft front, I am aware of the following possibly in development:

• Cockspur (a collab with another dev) Antonov An-26, in progress as of September 2023 but haven't heard anything lately. 
• Someone on the Official Forums was working on a Tu-154M, but I don't recall any internals/systems info which is by far the most challenging part. 
• Vaguely recall someone at FSDeveloper.com showcase subforum working on a Tu-144 but 90% of the early preview showcase threads end up dying. Again, systems are the hard part. 
• Nemeth Designs has said they want to bring their library to MSFS (Mi-2, Ka-26, Ka-32, Mi-24 multiple variants, Mi-17, etc) but they are down to a one or two-man show at most, and said *if* it even happens it'll take quite a while. I know they have a deal with Asobo though, and I think they are our helo provider for the mystery (but known it will be a helicopter) Famous Flyer/Local Legend for the January update. 
• Cancelled but in case it's mentioned - There was a Yak-40 in dev and mentioned on the Official Forums but the developer cancelled the project after misrepresenting his available team and resources following an ask for assistance.
• The Tu-134 as mentioned previously. The author is still active but I think is encountering difficulties and is now doing the "feeling out if it's worth it" thing. 

Soviet/Russian/Eastern Bloc that have been actually released:

1. Cera Sim Mi-17 Hip (new release: first patch/update coming in the next month or so)
2. Aeroplane Heaven Aero 45 (know as fairly buggy and lower quality but hey it fits the profile)
3. ATSimulations/Asobo/MS Antonov An-2 Colt (very well regarded and feature complete. Likely the best addon on the released list)
4. Deimos Su-27 Flanker (simplistic but visually nice)
5. Deimos MiG-29 Fulcrum (simplistic and visually ok)
6. Asobo/MS/Lotus (at least one of the devs of defunct Lotus was involved) L-39 Albatros (part of the Reno pack)
7. GKS/Aviasim MiG-21bis Fishbed (in-depth and visually fantastic but no longer supported due to the devs fighting for Ukraine. Possibly deceased)

It leaves the airliner field from this part of the world sparse other than the An-2, which is likely not what many people are thinking when they think passenger airliner. 

Here's hoping for some further developments.

Update: The owner/developer with SimUniqueLabs basically said that due to world events and his own circumstances he can't promise anything anymore, which I take to mean that an MSFS Tu-154 from him may not be in development.

Update 2: GKS is apparently alive and just announced the imminent (this week) release of an F-111 Aardvark. I asked about updates to their MiG-21 Fishbed and they said a comprehensive update is coming in January 2024. 

Some time ago, Cockspur announced they were assisting a Ukrainian development team with an Antonov AN-26. A few pictures of the main panel were uploaded to their Facebook page in September.  

https://www.facebook.com/photo?fbid=289137613863790&set=pcb.289137737197111