I’m pretty sure that many services keep your old email saved. Such information can be used for security questions “tell us information only account owner can know, so that we know we can proceed with XYZ support”. You have two options:
- Ask the support if they keep the old email adress and how long they keep it. They usually do not lie about such questions.
- Just create a new account and request an account deletion of your old one at least for those accounts who do not need/own your real data as real name and real adress and for those who have no high value (example: Techlore would not want to recreate a Techlore-YouTube-Account etc).
About phone numbers: I never share my number online for privacy and security reason (so I also do not use Signal etc). I would recommend not to share it where ever possible. If you rely on it, well, others may know more than I do.