At the moment, collections.abc types are strict aliases for their typing counterparts. This can make it difficult for intellisense providers to distinguish them and suggest the correct one. @erictraut mentioned that for pyright: microsoft/pylance-release#1001 (comment).

Although this would likely be a lot of code duplication in the short term, I propose to copy the type definitions to the _collections_abc.pyi module guarded by sys.version_info >= (3, 9).