Interesting that they're dropping the less-viewed but technically superior BuzMuzik - which, for instance, allows Facebook as well as SMS messaging - and on which they've previously withdrawn video voting, in favour of taking over a channel which still uses solely SMS and still has voting! Maybe they'll integrate some elements of BuzMuzik into Starz, mind.
Also notable that the chat matrix on Starz is on air longer in the day than that of Buz, and charges twice as much per message - perhaps that swayed the thinking? I'm guessing that in the run-up to the closure they'll try and sway the Buz viewers to swap to Starz, though I don't know if they'll all be happy to!
I'm also assuming an EPG reshuffle when Buz goes, presumably shifting CS Dance to 372 and shutting off 382 as it's a standalone channel further down the grid and so easier to get rid of.
One positive in this move is it does reduce the duplication in the guide, feeding two similar services into one and does free up a slot for CSC to do something else - and don't forget they've already got one placeholder, ?TV in the Lifestyle guide, which may see change given Sky's merging Entertainment and Lifestyle back together later in the year.
Not sure what the current Buz broadcast capacity will go to, mind, or where the 2am-4am block used for the new placeholder is coming from (the hours suggest, like ?TV, it'll be timeshared with an existing channel).