There was that leak that more classic SNK games might come to Steam some time ago, but nothing has appeared. Maybe that's the surprise announcement in April?
I thought that was a number of trademark renewals that ended up sucking as a humblebundle. I still hope they get to steam as well but I also hope the announcement is something else like confirmation on the SS rumor you mentioned, or a non mobile Metal Slug.
As for the April fools ideas, I hope they don't go SEGA on us who have in recent years announced MEGAne Drive (Mega Drive shaped glasses possibly for VR/AR gaming), Rappy Bird (a clone using sonic backgrounds and a rappy), and 2.5D Virtua Fighter 5 FS (complete with hadoukens, tatsumaki senpuu kyakus, shoryukens, and ultras) for various April fools. I don't mind the gags but I'd like them to be re-established as a pillar in modern gaming before they start messing around with that sort.