Just spotted a newly created account posting a suspicious link to a supposed "last update" in many games' comments. It seems to circumvent spam detection by posting with a delay.

I assume that using the Report function on one of these and describing the situation is enough for moderators to check the account and erase everything?

That should be enough. Just click the report button on one of the comments, describe what is happening, and itch.io moderators should suspend/delete the account.