Oh boyyyy. Judging by the sad state of the current game, this can only lead to more disappointment. Watcher may understand what that upper 1% for large raiding groups wants. But it's a very finite view of the game as a whole, and isn't very fun for a lot. Just look at the subscription numbers lost, and the raiding guilds that are no longer raiding.
If they were hoping to revitalize WoW, it certainly hasn't shown it. A steady decline of quality since WoTLK has taken effect. (Sure, we got some quality of life improvements and what have you) but looking at the long term really makes you question. Even setting aside taking a look at nostalgia through rose-tinted glasses, directing the raid scene towards ONE raid size for end-game is a terrible concept. It basically diminishes the work you have to do for tuning,... which I guess is probably a positive.. considering alllll the bugs the ten man tuning faced.
This man cares little about anyone but those who he's familiar with, I.E., those old 25-man groups. I'm sure he believe that as long LFR and normal and flex/heroic whatever exist, that he can make end-game exclusive to those sizes. I don't mind bigger raid teams, but I'm sure there are more than a few groups of people who preferred the 10 man scene, while also having access to end-quality gear. While more often than not, having to put much more effort into a fight than the 25 man counterpart.
Moving Watcher to this position hints at a few angles, honestly. And not really any of them are all that positive, when it comes to the future of the game and population of those who play it. Congratulations for him making it up the latter, but until he gets his feet wet and realizes that there's more to cater to. Eh.