Charlie already said in a podcast (https://www.youtube.com/watch?v=XVwpL_cAvrw) that they are not looking to make it extensible. That it's considered a feature that type checking works interchangeably across tools and projects.
Ruff's linting and formatting is more likely to get plugin/extension support at some point in the future.
Because ty was built out of the ruff code base, and is maintained by the same team, and the type checking abilities are intended to help ruff with linting rules in the future.
Ruff's linting and formatting is more likely to get plugin/extension support at some point in the future.