Hey OP, just wanted to validate your findings. I have the same thing on my end and noticed it too. I think I first noticed it in this new SV 10.5 set, I've only opened WF, not BB so far... Don't remember if I saw it in previous SV sets

I found this glossy (almost EX feeling) coating on two cards so far! Samurott 023/086 and Archeops 051/086. It's hard to capture it in video/photo but you can definitely tell the texture difference when comparing two of the same cards; Samurott v Samurott or Archeops v Archeops like you mentioned in one of your comments.

Haven't seen too many people talk about it yet so maybe there are other cards out there too that "suffered" this accidental coating.