pygame team member here
There's an important caveat: We provide an API for the SDL2 render system, and some functionality for up-scaling pixel art games on the GPU, but existing pygame 1.x games won't magically become faster by running on PyGame 2.0. They will be a little faster, because we have new, optimised blitting and drawing routines. To make use of GPU-based rendering, you will need to use the new APIs.