Stellantis did claim, that they are looking closely at FIA, what they will do with regulations for 2027. And Gryazin/Rossel being supported by the official manufacturer driving Rally2 C3 (doing quite good job at the moment) give us a clue, that they do explore options. Well I hope so.. Fingers crossed.
Lancia (being part of the Stellantis family), start doing on a Rally4 car... But that's it. And recently Stellantis being all over Lancia don't bringing them enough money I don't believe they will enter with that brand.
Skoda, hmmm don't know, but they are so quiet. They really need that challenge being in the top. They are building some sort EV SUV concept race car.
Subaru was also mentioned, but that was only wish from Toyota boss. Ever since it was quiet about them.
Ford are saying if the regs will be right for them they will invest fully in rallying, probably M-Sport will still be the team to do that.
Alpine was in the game too but they want to be the championship fully EV. But even if it would be, I don't think they really have interest in rallying at all.