The projections care more about his more granular statistics. His strikeouts and walks, whiff rates, etc.
And the projections are probably still not quite ready to think that his HR rate is not unlucky at all.
Here are all the 2022 SP who pitched at least 90 innings and had a K% of 25% or more:
Strider, Rodon, Ohtani, Javier, Cole, Snell, Greene, Woodruff, Scherzer, Burnes, Cease, McClanahan, Luzardo, Lodolo, Nola, Gausman, Morton, Kershaw, Verlander, Peterson, Severino, Ray, Kikuchi, Castillo, Gallen, Wheeler, Ashby, Cortes, Springs, Gray, McKenzie, Darvish, Giolito, Mahle, Bieber.
If Kikuchi is, truly, a pitcher who can consistently strikeout 25% of batters but give up 2 HR per 9 innings pitched... then he's a statistical unicorn. He's the weirdest pitcher ever. He's unlikely to be the weirdest pitcher ever. Something has to give.
Here are the pitchers since 2000 who have done that in a sample of 100 IP or more (25%+ K% and 2 HR/9 or more)
2021 Tarik Skubal
2021 Andrew Heaney
Skubal was fantastic in 2022 before getting hurt.
Heaney was fantastic in 2022.
Not saying Kikuchi will be great or anything but it's pretty easy to see why the projection systems think he is better than his 2022.