I cannot speak to the roadmap, however as of now, our Plugin only works with VS 2015. From what I understand about Visual Studio though, you can install multiple versions on the same machine as long as you install them in their order of release (i.e. VS 2015 first then VS 2019).
You can speak with your Pega contacts to get any information on the roadmap or to make feature requests.
The idea is to move away from using an external IDE (i.e. Visual Studio, especially since Microsoft has stopped providing the isolated shell). We are about to share more details in one of the PegaWorld iNspire sessions, so make sure to sign up and listen in: https://www.pega.com/events/pegaworld/agenda/robotic-process-automation (minor spoilers: we will provide our own IDE)
If you haven't registered already - PegaWorld is free this year, and signing up only takes one minute of your time: https://www.pega.com/events/pegaworld. PegaWorld iNspire is a virtual event - Tuesday, June 2, from 9:00 – 11:30 a.m. EDT.