i get at times when blizz says we have detected a irregular pattern (which is actually true) on your account and they won't let me log in.
then i click on the link, and it tells to secure computer and to check my email and follow link to reset password. after PW is redone from my email link....no problems.
as for your case, blizzard or battle.net would not ever know a account was stolen. they would not know till you contact them and tell them it was stolen.
i and alot of players have gottten those phishing emails claiming account is banned, stolen, violations that will lead to ban, etc. they look at official, wanting verification info etc. but they are fake and attempts to steal your account. they also offer pets, mounts, gear, etc. they have close looking but not official sites like wow.blizzard.com
friend of mine fell for it in WOTLK, he got a email stating he was eligible for T10 gear, etc. to log onto the armory link below, if took him to a page that looked like wowarmory, he logged in, boom account stolen. he had to contact blizzard customer support to work on getting his account back. they were able to restore 4 of his 80's with the gear they had, however all gold and items in bags could not be restored.
if you got a email stating your account has been stolen, it was fake. you opened it, answered it, put information...your account is gone and actually stolen at that point.
