One of my goals for Magritte and Pier is to slowly move to
3.9, because it offers things (Pragmas) that will make our
life easier and that I have been waiting for a long long time
now. For now I will try to keep compatibility for 3.7, 3.8 and 3.9.
I would hope that 3.8 remains the primary target at the very least until
after 3.9 is actually released.