You should have used / created an EA Account to sign up for Labs, so as long as that is still the same for you, I do not see how changing your associated email address should change that.
Some players have discovered you can check your Early Access Beta status by requesting a download of your data in "Security and Privacy" within your EA Account Settings:
https://myaccount.ea.com/am/ui/security-privacy/download
If you want to try that go for it, otherwise you could reach out to EA Help as well for assistance:
Hope that helps and see you on the Battlefield!
