I can now confirm that today I saw a major supermarket (no, not Tesco) with their ordinary eggs in 2 different cabinets which, by the sound and feel of the cabinets, had some refrigeration on. Probably not on full tilt, but they seemed to be switched on. I couldn't see a temp gauge.
Auchan and some Carrefours in Kraków have their eggs in the fridge...that would make the claims of it being illegal pretty far fetched.