Would be really cool if we could make a XY Ladder. I know that XY evolved to ORAS but I think that a XY Ladder is a good addition for the server. First good argument is that you don't really lose something from implementing it. Second thing is that the server attracts people which ends up getting more and new players. I mean everyone wished to kinda play XY again, but besides tours and private battles there is no way to do that. So as a result people may be excited and download PO again.
There is actually a no rule XY tier. However I've seen a lot of people complain they can't find battle in it were I had to tell them to go to team builder to change their gen to ORAS. /changetier XY
While I do support the idea, you'll surely get an answer type 'we have already enough tiers failing so why add another one' lol
I think this would be really interesting to implement, as it could possibly give us an advantaging over showdown as they would not have this format...