My partner just created her #Threads account and the account that showed up on top as suggestion to follow was mine. However, I don't have a Threads account.
Basically, anyone who has an Instagram account, #Meta is automatically creating a shadow account for them and also allowing users to follow those shadow accounts. My partner had tonnes of follow requests as soon as she made the account.
Not only that, they create a ‘shadow’ profile of you even if you don’t have any meta accounts at all.
https://www.newsweek.com/facebook-tracking-you-even-if-you-dont-have-account-888699