IMO forcing opponents to reveal their hand is at least as much of a thing to do as it's .

Revealing an opponent's hand is Blue and Black. With the lone exception of (((Planeswalker's Mirth))) (a very old card), every white card that does this is either also blue or black.

I would shift this to blue. Stellar draft pick btw.

I'm very familiar with the color pie, so you can most of the time assume that 'weird' cards like this, Forgive and Forget, and Dejection are color pie experiments made with purpose in mind - not on accident.

I would also say that revealing hand isn't really something black does per se, but it's something that needs to be done in order for the discard cards to play correctly. For example, I don't think there's a single black card that would reveal an opponent's hand without the intent to discard something from there. Besides, I think many of those are 'look' not reveal - a minor difference, but still.
In any case, here that etb ability could almost been seen as just trinket text with flavor connotations.

Except for the spirit creatures, there's a lack of flying in the set so this quite evasive indeed.

While I haven't encountered it so far in playtests, I've been considering whether this should look at a hand instead of revealing it to avoid any potential confusion with proclaim.