Those ingame warnings are automated and untraceable.
That means that the account has a past verified penalty on it. A week suspension is a second offense.
This is not related to your suspension. Warnings are a fairly new system that lets you know other players are reporting a character on your Battlenet account. It hopefully gives someone time to stop whatever they are doing to annoy folks - like maybe spamming an advertisement. They are unfortunately not character specific, and not always delivered in a timely way. They are across the whole account, all game versions. A Classic char could get reported for spam, and the warning could show up when the person logged into their retail char. Those are automated and not something CS can see. They can’t tell you what other players reported you for. Here is an article about that.
Other players would have no idea what you got warned for. None. Not even CS can tell you.
Asking about that is not what led to your suspension unless it somehow violated the code of conduct in game. Trolling, profanity, masked profanity, slurs, insults, spam, etc. The suspension is likely from whatever led to 5 warnings.
For a while they sent lines, but stopped. Do some google if you want specifics.