If a way of signing in presented a verified email address matching an existing SIMCOAI account, it used to be attached to that account straight away, with no confirmation. That is fixed: linking now only happens when you start it yourself, signed in as the account you want to add it to.
There's a new Connected accounts tab on the Security page for this. It shows which providers can sign you in today, lets you add another one, and lets you remove one — you always keep at least one way in, so the last one can't be disconnected by mistake. Adding or removing a connected account asks you to re-confirm your password or two-step method first, the same as every other change on that page.
What changed
Connected accounts makes adding another sign-in method a deliberate action from inside the account. A matching email address alone no longer causes a newly presented provider login to be linked automatically.
The Security page lists the connected providers and offers controls to add or remove one. Changes ask you to confirm your password or second-step method before they take effect.
Before and after
Before this update: A provider presenting a verified email matching an existing account could be attached to that account without the explicit linking confirmation introduced by this update.
With this update: Linking starts from the account you are already signed into. Adding and removing a connection require confirmation, and the last remaining way to sign in cannot be removed by mistake.
What it means for you
Open Connected accounts in Security to review the providers attached to you. Add a method only when you intend it to become a way into that account, and remove connections you no longer need.
The protections help preserve access as well as prevent unintended linking. Available providers still depend on the account’s enabled options; an email match is not a substitute for the linking process.