[interestednovice]

That’s a bit like what happened with Satellite, with the final region to launch being BBC One South East HD and the feed actually being physically the same satellite stream that had been BBC One (Network) HD - by that point broadcasting to the SE only because all the other variants had already launched. In that case, they stopped blanking things with the red screen also a day early and EPG changes followed the next day. Presumably it’s some sort of preparation to ensure that the regionalisation is not “blocked” by the red screen accidentally, so they make certain technical changes early on purpose.

The “network” feed was always derived from BBC One London anyway, so it is not surprising in a way.