At the moment anonymous posting is possible, yes, but not within the parameters that you’re outlining.
Currently (if enabled) it is available at a per member level (across the entire forum) and a user has to be logged in.
A new account is created each time someone goes into anon mode so admins/mods don’t have visibility of who it is (outside of assumptions that can be made around who else was online at the time etc).
Edit to add: I think more work could be done to make this more ‘usable’ but at the moment it does offer a solution for members that would otherwise not feel comfortable engaging or asking a question – esp in professional communities.
It is open for abuse, but some of that comes down to how you manage behaviour within your community. I’d suggest that it’s not appropriate to even enable the option in many communities.