There are some big brain companies who will block you if their name appears in the email address. Like Discord. You can create an account, with discrod@example.com. But a seconde later you will get an email that your account got band.
What you say is often true, but in the case of Discord, at least in my case, you are wrong. My Discord email address is discord@xxx.com, and I am still receiving emails from them.
It happend to me when i created my account in 2025. Within seconds of verifying the address I got a email that my account was band for TOS violation. I than created a seconds account (within minutes from the same IP) only writing "dc" instead of "discord" and that worked. ¯\_(ツ)_/¯