From #977 (comment)

Second, would it make sense to rename the top-level DeleteDirectory() method into TryDeleteDirectory() as well? My rationale is that it (1) does not ensure directories are indeed deleted and (2) does not provide any direct feedback to the caller (only BaseFixture.Dispose() at the moment) that it could not delete a directory.

Why not? However, by convention, TryXxxx methods expose a certain signature (a returned bool and an in out param). I'd prefer using a name that doesn't conflict with a known pattern.