>>718410502
Only if they advertise. That's how they avoided Nintendo's wrath for so long. They stated themselves that Nintendo and TPC are fine, as long as you don't market it, and most Pokemon buyers do not buy Pokemon for the combat. You know it's true, or else the battle frontier and stuff wouldn't have been removed from mainline entries.
But considering how draconian they are with their IPs in the first place, Showdown may go invite only if the lawyers go sniffing around. I I don't think they'll have much to fear as Champions is more for VGC's sake, and Showdown can't interact with or take away from VGC at all.