Ghost of Tsushima was always going to have a sequel. It's inevitable. Sony just isn't going to waste the opportunity to make a follow-up to one of the best-selling PS4 games of all time, not when a live-action adaptation by Chad Stahelski is also in the works. However, there is a difference between presuming that Ghost of Tsushima 2 is in development and knowing that the studio is working on it and we have just found proof of the latter.
According to a job listing for an encounter designer at Sucker Punch Productions, the first-party Sony studio has started development on Ghost of Tsushima 2.
Of course, we're not ruling out other possibilities either. The job description states Sucker Punch will put the candidate to work on delivering "interesting and varied encounters in an open world, with a particular focus on melee combat and stealth." Both stealth and open-world parts would fit right in with thelong-rumored fifth Sly Cooper game. Then again, we don't think that the stealth platformer series had a lot of melee combat, but who knows?