This is a pretty common issue, especially for school accounts that students lose access to when they graduate. IIRC your account or Repls will not be affected, but you may not be able to log in, requiring you to probably contact Replit directly with some sort of proof you own that account.
I’d do what @NateDhaliwal said to avoid any sort of risk though.
Yeah, it looks like you would have to provide your old password, which wouldn’t exist if you signed in with your Google account. IIRC you would enter your Google account’s email and it should work?
If you are still logged in, you can simply disconnect the Google account and use another email by going to https://replit.com/account. There should be a button there somewhere to unlink the Google account (then Replit will use it like a normal email, and you can switch emails).