Weird warning on the wins page?

You did nothing wrong. It is there for all users.
See recent update: https://www.steamgifts.com/discussion/e9zDo/change-log

I've got it too and it's new for me too so I think everyone sees it

Damn these new rules! Now we're supposed to activate our wins too? ;_;

Uh, neat new update.
By the way, I may be wrong, but SG has a color code for messages:

Green - Something positive is happening to your account, successful action
Yellow - Notice, note
Red - Something is affecting your account negatively/you cannot proceed with an action

Just an assumption, but I think if you had done anything wrong, the message would be red. :P

yeah i also think the same. i'd write it this way:
green - positive
yellow - neutral
red - negative

Got it too, understand it if you are new and all, but after a certain point they are kinda unnecessary.

Did I do anything wrong?

nope... but i sure can't wait for all those people that did do something wrong to go and see that. ^^

Thanks for this thread! Glad to see it's not just me.
I was worried I messed up somehow, even though I always activate everything I win.

XD should have check earlier before i look at all my win to see if maybe i had forget to active something

se por exemplo,ganhei uma dlc que ja tinha,como posso devolver ou algo do tipo?