I am just adding to what @manj_k has already stated in the comments against the question.
what is the generic name for the Ask LibreOffice interface? Is it still a forum or is there another name for this style of interface?
I refer to this site as a “forum” although it is more correctly a “question & answer style site” (list of similar sites), such as those in the StackExchange Network e.g., Stack Overflow, Super User, Ask Ubuntu, etc.
How do users make suggestions about this interface to the community?
In addition to raising a question here, you can also post a question over on the AskBot forum. Getting changes made is dependent upon what is considered under LibreOffice / The Document Foundation authority and what is considered under AskBot authority. If this site has a problem (bug) then it is an LO issue and needs to have a corresponding bug raised via the bug submission assistant using the WWW/ASKLIBREOFFICE component. If you are requesting an enhancement, then it is likely your are requesting a change in the underlying AskBot software this site runs on and so you would need to make this request on the AskBot forum (they do not appear to have a bug tracker).
I recently learned there used to be an actual forum.
That forum was the precursor to this one and is still active. I am a moderator over there. I personally find it easier to use than this one and it currently has upwards of ten times the amount of traffic (could easily be much more). That may change over time, although the simplicity of use is a big advantage IMO.