New rules for submitting maps.

Why do you assume that new sections won't be added? The current voting suggests otherwise.

Well, for now, slightly more people are voting for tags. According to the survey plan, it's better to implement the option that satisfies the majority of people, rather than the one that seems best to a portion of the voters. But I'm open to discussing that as well.

By the way, why is the number of players needed for single-player maps?

It's not needed. As I mentioned, it's only for multiplayer.
In general, I envision the headings something like this:

Journey-Dyrman-Scenario[L]
Bay of Destiny-Subjugator-5 players[XL]
Map with alliances-Just came up with the author-2x2[L]

Not necessarily in this order, of course.