The version numbering here is an absolute mess. Chandler/Monica 2 is actually Monica v5.0.0-beta, which would logically mean that this newly announced Monica 3 is actually Monica v6.x.

Chandler/Monica 2 (v5.0.0-betas) never made it out of beta. It’s had five beta releases but no stable release. The stable 4.1.2 version is actually still the original Monica 1.