As described, the licensing system will fail you into readonly locally unless you subscribe Office Clippy 365, buy Office 2024, apply Office 2021 updates, or (not listed) apply third-party licensing cracks for Office 2019.
Presumably we’ll know soon if network firewalling the licensing server helps, but I expect it’ll just delay the intentional failure by a few months at best.
Presumably this will happen to Offica 2021 in two years, too, so it's actually worse than you say.