So... just got a Steam profile restricted for...

The answer is probably neither. Probably an automated system restricted you for using sus words such as "you won".

AI mods flagged it. It's better to say something like, "Hey, "x game" is waiting for you on SG. Cheers!" or somesuch. Don't mention giveaways or winning. There are too many Steam scams that use that terminology, so AI moderation is keyed to it.

Think it is Steams automated scam detection system. There were some many threads here on SG about this over the last year.

It's been happening a lot lately. Just open a ticket in support and explain the situation, as far as I know everyone has had the restriction removed after that.

I believe people recommend against saying gift or such, or even posting on Steam. But maybe "spacecat has visited" would be good.

Better to contact through SG.

So much Deja vu. Why are people repeating the mistakes of others every week?

So Steam admitted it was a mistake on their part and lifted my restriction:

"It appears that your account has been locked for suspicious content. I just checked the content in question, and it appears that a mistake was made.

We've gone ahead and removed the lock.

If you have any further questions, please let us know - we will be happy to assist you."

How strange.
As someone said already, the only reason I can think of is they may took you for a scammer.
I recently found some comments on my profile from Chinese accounts saying they wanted to take me to hotels and weird stuff like that. It was a friend of mine who told me about those messages. Obviously I don't know people from China. Probably there is a bot invasion and they are just being extra picky.

It baffles me how frequent this has become lately. Maybe cg should add a warning on the profile of SG users, next to the link to their Steam profile.
"Don't tell them on their Steam profile that they won, fools. Or do you want to get banned like a generic scammer?"