I just saw this sym skin today and tried to look it up in-game but couldn’t find it, and yes i tried the “check all” option from the filter
Brig apparently has an overwatch league skin too? And zarya i think has a skin where she has a black ponytail??
the wikipedia is the only way as afar as i know (but not in-game, so i’m not answering your question in the slightest)
filtering by unowned might be the best way, but some exclusive ones still might not pop up there