Pick (when it was Sky 3) used to occasionally do it as well. I note the Eggheads episodes are tagged as "new" (which seems to imply they haven't been aired under Sky ownership) but have these episodes aired before? That might explain why the announcement is early, because when playout moved the issue affected quite a few programmes (presumably a marker or whatever it is that triggers the announcement is in the wrong place on the file) so it'll probably continue to do it until somebody notices.
I notice on social media they're very keen to big up the revived Millionaire. Last time they went on about Robot Wars and then the new Robot Wars appeared on the channel a short while later. I expect to see an announcement soon about Jeremy's Millionaire (followed by EPG
entries that don't distinguish which era they're airing!).