Changing Apple ID Email to another one, used previously with another Apple account

Wait another 4 years. It's better than it used to be when you could never reuse one. Read the article in full by the way. If you hadn't deleted the account you might have been able to use it a lot sooner by removing it and waiting a month instead.

From: How to delete your Apple Account - Apple Support

“Can I use the primary email address for my deleted Apple Account to create a new Apple Account or with another existing Apple Account?

No, once your Apple Account is deleted, you can’t use the email address that you used with it to create a new Apple Account for as long as Apple retains the one-way hash of the email address. For third-party (non-Apple) domain accounts, the one-way hash is deleted after six years. For other accounts, this is retained according to Apple's retention policy, which is reviewed regularly. In addition, you can’t use that email address with another existing Apple Account except as a rescue email. Also, if your primary Apple Account email address is with a Custom Email Domain, it can never be reused to create an Apple Account after your Apple Account is deleted, even if the domain ownership changes.”

According to Apple I have to wait 30 days if non-Apple email is just removed from Apple Account,

If you remove an email address that isn’t an iCloud email address from your Apple Account, it can’t be associated with another Apple Account for 30 days for security reasons.

and 6 years if Apple Account with non-Apple email address is deleted. It's huge inconsistency for me. What's the difference between "releasing" non-Apple email address by removing it from Apple Account or by removing whole Apple Account?

Also - any idea what's current retention policy for Apple email address (like iCloud.com)? They claim that retention policy is reviewed regularly. I want to use iCloud.com address that was bound to Apple Account deleted many years ago (at least 3). Still, it's not available for reuse. That address is the only missing part of my "perfect" Apple Account configuration (fortunately they allowed swapping primary and alias email addresses in 18.1 eventually).