If Only eevee gets the move
Then whats the freaking point? its a garbage pokemon on its own, and while its evolutions are strong, they're almost always outclassed (the exception being jolteon) by nonlegendaries, as they're more or less a holdover until you get better pokemon of that type
Which is why I dont get the "all eevee caught during the event" thing, yes it has an exclusive Z move, but its a status move, not an offensive move, keeping in mind its stats are so abysmal it cant event do anything on its own. That seems to suggest that *only* eevee will be receiving special moves, as it said nothing about its evolutions, which makes me wonder what is the freaking point of it?
yes you can say lets go eevee, but if that were the case, why not do this back when the game was announced, my only thought is 2 days are for day 1 being for leafeon/glaceon, and the other being for the other if gen IV's released before the event. (But again, it states only eevee will be getting a move)
Thats also not including that most other CD's were more or less stock up of candy for evolving high IV pokemon you had prior as wild caught pokemon have more often worse iv's that hatched pokemon
Answers
Yes, if you care about shinies. The only reasons I like shinies are:
1) For legendaries, it's an auto catch if you hit it, so you can pinap it and get 3 more candy.
2) For all pokemon, if you do a raid with a bunch of them, sometimes you lose track of which one you're on. Putting a shiny in a certain position lets you know when the last one is up, etc.
Other than that, shinies are purely cosmetic to me. Sure, I get that collectors will want shiny Umbreon, etc. And I welcome them to them, and would willingly trade with them for something more valuable to me.
Finally, we still don't know a lot about the exact mechanics of the day. It's likely something will surprise us, so I see zero point for the original poster fretting about the exclusive move.
Over and out.
