Seems like a few old scores are being settled during this drama. It wouldn't surprise me if a lot of people on the side of RubyGems are avoiding commenting in case any legal disputes play out.
If a8c wants WPE to mirror the plugin and theme repos, they maybe should have asked for that. MM led out of the gate with his now-well-worn "existential threat" rhetoric and actually managed to escalate it from there. As one reddit commentator put it, "you catch more flies with honey than with lighter fluid".
The WP ecosystem needs mirrors anyway, but at this point I think it needs outright alternate repos, not under control of a8c in any way. This could be an attractive proposition to plugin/theme devs, because in this case, MM has been poisoning his own well for some time now (https://meta.trac.wordpress.org/ticket/6511). What are the odds that MM will accept a patch to WP core that allows alternate plugin/theme stores?
At the rate things are going though, a hard fork of the GPL'd core is looking more attractive every day. It just needs a catchy name. ClassicPress is already out there, but ... meh. How about FreePress?
Well,
1. He's not fighting Ruby Central anymore, he'd be fighting the Ruby core team.
2. He's going to have a tough time asserting copyright on a name he didn't come up with on a project which shipped v1 before he joined.
3. If he believes the trademark belongs to the community, the right thing to do would be to transfer it to Ruby Core then, right?