Right now it's possible to have leaks due to bugs in the autofree engine. Once it's stable, there will be no leaks.
For mutable objects shared across threads, reference counting will be used.
For mutable objects shared across threads, reference counting will be used.
V has the same issue and autofree will not be able to fix it.
Reference counting is also necessary even in entirely single threaded programs to handle some situations.
It's concerning you state things that are categorically false with such certainty.
The problem with V is that the author makes astounding claims and when people push back on that even slightly they get harassed. Even your comment nit-picks mine over technicalities while ignoring the obvious issues with the author's.
Given how many of the "features" of V are completely unimplemented or only work in the most narrow of edge cases, it's not clear to me why so much grace is extended to the author who's generally been unable to deliver his promises all while collecting a tidy sum on patreon.