There are some proposals floating around to evolve PlusCal. Probably the most prominent is Distributed PlusCal[0]. There's a programming language lab at UBC which is also doing a lot of experimentation with transpiling PlusCal to Golang[1]. They presented a paper at the latest community event.

The PlusCal-to-TLA+ transpiler is considered part of the core TLA+ tools and will definitely keep being maintained.

[0] https://conf.tlapl.us/2020/03-Heba_AlKayed-An_Extension_of_P...

[1] https://distcompiler.github.io/