[Neil Jones]

They've annoyingly added a massive "New to Challenge" DOG tonight (haven't noticed it before) for The Crystal Maze, despite surely showing it multiple times before.

Yeah that's the first time that's appeared this run.
But yes, might be that they haven't shown it for a very long time - it used to be it only appeared on stuff that hadn't aired under Sky ownership, but that argument/use case fell apart when they started sticking it on stuff they just hadn't aired for a while.

I wouldn't be in the least bit surprised when they start the Blockbusters re-runs next month that'll have a "New to Challenge" DOG on it - and that first/early series of Blockbusters debuted under Sky ownership anyway - previously it was only the 90s episodes that were seen ad nauseam.