Would be a good idea but the current 'fun mod' servers (if they are even still there) are rarely used right now. Though this would be a nice for the people who do love creating servers to play fun mods because they could play with 7+ other people (assuming this type of server will get used) and socialize as well as have fun.
You could just make your own room. If Hampa were to add public rooms that mod rotated, it would just increase the work load that the gm's have because they have to be constantly changing the mod in every room.
You could make your own room and probably about 1 in every other...50(?) fun mod servers will actually get a bunch of players (unless you have a few friends to play with).
I am no coding expert but I assume there must be a code the GM's could use to change mod every few wins or something like that. And hell, if they want to get really complex they could build in a voting system which chooses two random fun mods from a list the GM's have selected and the users can vote (/vote (mod name)) etc...
But that's just not worth the effort in the end I guess.
If this idea does get accepted I suggest GM's only make one server like this. Toribash is always more fun with more people in one server, especially on silly mods and at least this way if the server doesn't get used, at least there is only one of them and it isn't taking up any space.