I think better phrasing would indeed be something like "several former core developers" - of course we can't really measure up to the size of the original community, and don't yet have any paid developers (like Araq and narimiran [1] in the mainline - although since the end of September there were not a lot of activity on their part as well - [2] ~30 commits (~23 that are marked `[backport]`) and even less [3] for narimiran)
[1] https://forum.nim-lang.org/t/8540#55418
[2] https://github.com/nim-lang/Nim/commits/devel?author=Araq
[3] https://github.com/nim-lang/Nim/commits/devel?author=narimir...
Right now, it seems like most of the work on the mainline seems to be done by community members.