I think that's the real reason. He's just tired of having a car that it almost impossible to set up good, and then breaks when he's fighting for the win.
As much as many of us want to see him back, I don't see a point putting him in a Rally1 car for just one season, since the car will be discontinued anyway and Hyundai not even building WRC27 car....
Róbert Kolčák (Chooligan Racing team) will compete in the full ERC 2026 with Hyundai and Michelin Motorsport
Jakub Matulka would like to continue competing in ERC in 2026. source: https://rallypl.com/matulka-celuje-w-starty-w-europie-wywiad/

At least based on this, we won't see him in WRC next year. Full shut down. https://rallyjournal.com/ott-tanak-shuts-down-talk-of-a-wrc-return/
Ott Tänak - Future champion?