I’d also advocate just removing hyphens and requiring underscores, at least for 1.0. Post-1.0, new facilities (like namespaces) could be added, and restrictions on names can be loosened if it’s determined that they are too tight, but it’d be impossible to tighten the symbol-naming restrictions post-1.0 in a backwards-compatible way. So the safe path forward seems (to me) to be using the more-restrictive option until the less-restrictive option gets more fully fleshed out.
For whatever it’s worth, I also prefer hyphens to underscores aesthetically, and I also like the ability to rename crates on import, so the status-quo isn’t that bad, for me. BUT I also feel like the current design is not that future-proof (if something like namespaces get folded in, in particular), so rather than have 1.0 block on getting the right design right now, I’d like to see the current behavior stripped to its future-proof essence, so that a better facility could be added even after 1.0 (if that’s how long it takes to design).