I self-describe what I'm doing as squatting in the associated commit messages for the squatted crate boilerplate, but if I go on to release a usable library under a name I've squatted, I don't consider what I'm doing wrong, especially in absence of a formal policy.
I consider it quite useful to be able to reserve names I intend to use in advance.
If there were a formal policy condemning it, I would definitely think twice. I'd probably still do it, but feel bad about it, whereas today I'm elated to claim certain names and rather enjoy the absence of a namesquatting policy.