More particularly its mandatory if folks want to use multiplayer. Since thats all HD2 is that effectively bricks the game outside psn countries. In Ghosts case, its single player, which doesn't require it, (per their devs), but does have multiplayer elements which would require it if you use them.
Yes, Sony started enforcing a requirement to link a PSN account in order to be able to keep playing Helldivers 2. This was months after launch, after being sold in dozens of countries where people can't make PSN accounts. Sony responded by just delisting Helldivers 2 from those countries. Looks like they're doing the same thing with Ghosts of Tsushima and delisting it from countries that can't make PSN accounts.
So they stepped back the login requirement with the whole "We heard your feedback, Gamerz!" line, but are clearly getting things set up to just do it later anyway?
I perceived it as:
“We heard your feedback, as such we fired the community manager, and will hire a new one who will be capable of keeping the community quiet”