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?