The v2.1 branch of moonjit specifically aims to remain "luajit-like" in the sense that it is the explicit goal to make sure we don't add incompatible features and we definitely don't make it so that if Mike Pall decides to continue development after a year (which he appears to have done, although one can never be sure given his record over the past few years), we can easily enough merge patches.

The master branch is where moonjit development is more active with people adding 5.2 and 5.3 features and new architectures too. It is in a way a different direction from luajit (since Mike specifically stated that he intends to remain incompatible with stock Lua because his dialect is better) and hence may not necessary converge with luajit if it ever actually comes back to life.

The last time Mike Paul pushed anything is almost a year ago until two weeks ago based on the two RSS feeds I use. The Git commit dates could be unreliable from either cherry-pick shenanigans or him just not bothering to push the changes until two weeks ago.

Maybe compare your feeds with:

https://github.com/LuaJIT/LuaJIT/commits/v2.1

I see quite regular commits there?

The last release was a beta from May 2017.