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.

You can try and later post peertube/youtube link. Nobody can really guarantee that it will be interesting for them until they see it.