Yet SIE still released Rise of the Ronin almost 4 years after Ghost of Tsushima.
I felt for the man in 2021, now he's clearly STILL butthurt about it to the point of obviously making shit up, LOL at the poster thing.
Hermen wasn't the head of PS Studios when GoT, Rise of the Ronin were greenlighted, or when Days Gone 2 was going to be pitched to PS Studios (around early 2019, around DG1 release). Back then the PS Studios (SIE WWS back then) head was Shuhei Yoshida, with Shawn Layden as chairman. Hermen became head of PS Studios in November. But according to Ross never was pitched to them because local management inside Bend blocked it, not the PS Studios or SIE heads.
Besides that, after making some market research they could have seen that maybe they had enough market for two open world samurai IPs but not for three or four zombie games (remember that in 2019 they were working on TLOU2 but also branched out TLOU Online making it another game and just had released Days Gone).
Also, Hermen & Ryan did include Days Gone in the PS Plus Collection (was some sort of their"best of PS4" selection), ported DG to PC and started to make a movie about it. Meaning, they kept supporting the game/IP.
We also now that they have been transitioning to have around half of the projects under development being new IP and around half being existing IPs. And back then in 2019 they were working on many sequels, so maybe at that point specifically they thought that it was better to have a new IP instead of another sequel.
So who knows, maybe in the future after this new IP, or before if they grow enough to have a 2nd team, they could do a Days Gone sequel. If having zombies is seen as an issue in market research they can always tweak the enemies to make them less zombie-like. They can use whatever they want, as could be rival biker gangs, military robots/drones, cyborg soldiers, mutant predator animals, aliens, PC fanboys angry for having to spend half a minute creating a PSN user or whatever they consider that can attack in a horde/pack.