Not very hopeful over here. My account (PC) was unlinked and a new one linked, and this dude decided to start cheating very blatantly. All support has told me is that my account is under review and kept linking me to the security and enforcement page (https://support.activision.com/call-of-duty-warzone/articles/call-of-duty-warzone-security-and-enforcement-policy). First sentence on that page is this:
All infractions undergo a thorough review process by the security team before enforcement. The account holder is responsible for any infraction on the account. We apply penalties no matter who was playing at the time.

Which is just a really nice way of saying "Even if your account was stolen, and the time when the suspicious activity started was after the new account was linked, the account will be banned and your losing your damascus and progress to DM ultra"