To put the drop into the context of the big picture, here's the last year, 5 years and max graphs:
Under their PlayStation PC publishing label yes, but they published may other PC games with other labels:
- In the '80s (started in 1983/1984) Sony made MSX computers and games for them, some of them developed in my hometown.
- During the 90s also published PC (and Nintendo/Sega) games as CSG Imagesoft/Sony Imagesoft/Sony Electronic Publishing, which part of it ended merged with other team to create 989 Studio and other part remained as Sony Interactive PC Software America (which published Wipeout).
- In the '90s Psygnosis, while acquired by what now is SIE developed games for PC (plus Saturn or N64) like Wipeout, Wipeout 2098/XL, The City of Lost Children, The Adventures of Lomax, Toy Story, Monster Trucks, Shadow Master, Rush Hour or both Rollcage games to name a few of them.
- As Sony Online Entertainment (originally owned by what today is SIE) they published games like the Everquest series, Matrix Online,Wizardry Online or Pirates of the Burning Sea, Payday, DC Univers Online, Bullet Run or Vanguard: Saga of Heroes since the '90s until they sold it in 2020.
- They published as Sony Music Entertainment (Japan) Inc. / UNTIES several games in Steam since 2017 as TINY METAL, 3rd eye, BATTLLOON and The Midnight Sanctuary.
- Sony Pictures Virtual Reality also published games and VR experienes on Steam since 2017 like Ghostbusters VR: Firehouse, Jumanji: The VR Adventure, Ghostbusters VR: Showdown, Groundhog Day: Like Father Like Son or Spider-Man: Far From Home Virtual Reality.
TLDR: Sony has been making PC games since forever using different labels.