Interesting.
Especially since AFAIK neither Zwift nor Rouvy have a profile for recumbents. I'm not familiar with any of the other plethora of trainer platforms (Trainer Road, Sufferfest, ...) but it would seem to me that in the interest of "level playing field" the UCI would insist on that.
But to be honest I don't really know that much about Esports rules or competitions so it could be that it doesn't matter.