Flask API is certainly on pause while 3.1 and 3.2 are addressed yes.
After that it depends on what I feel is the most productive use of my time. Perhaps general purpose Python API tooling, that includes Flask as one of the options, or perhaps work on hypermedia stuff that I've got in my head.
I like the sound of general purpose API tooling! In developing small services with flask, I've found myself reusing the same serialization code, input validation code, etc. You might be interested in Marshmallow, a minimalist serializtion framework. [0] I've enjoyed working with it, especially with Flask. I believe Flask-Restless or Flask-Restful uses it as well.
I'm developing a system that, among other things, could be an even more minimalist alternative to Marshmallow [0]. I actually haven't seen Marshmallow until now, it looks very nice.
After that it depends on what I feel is the most productive use of my time. Perhaps general purpose Python API tooling, that includes Flask as one of the options, or perhaps work on hypermedia stuff that I've got in my head.