

It depends on the instance. I created an account on mastodon with guerillamail which would be even more suspicious for an average website than your alias email. A tip, if you do not mind using icloud email, you can even create one with some effort without giving real personal data and using apple hardware (Virtual machines ftw), you can take advantage of its free alias email addresses which would be accepted even on most strict websites.
Sudo had many vulnerabilities in past some of them unpached for years and it is bloated with unnecessary functionality that increases the attack surface. Doas is more secure and minimalist for example. Not an expert to say if Ubuntu approach is correct but I appreciate their effort.