Honestly, I think this is probably the best way they could handle the transition. Ciri taking over as the main protagonist makes sense for a new trilogy, but completely removing Geralt from the story would have felt strange after everything that happened in the previous games.
If Geralt is actually given a meaningful role rather than just appearing for a short cameo, I'm all for it. There's also a lot they can do with the relationship between Geralt and Ciri now that their roles have effectively changed. Ciri has to step out of his shadow eventually, but that doesn't mean Geralt needs to disappear from the world entirely.
The 2028 target is a long wait, though. Hopefully the extra development time means CD Projekt can really take advantage of Unreal Engine 5 and deliver something polished rather than rushing it out.