I think it would be so neat to have another plaza! My idea is that it would be some sort of mountain, forest, or campground where we can access new minigames such as throwing horseshoes, archery, cornholes, canoeing/kayaking (maybe even full on boating with other boat sports?), frisbee, etc. If it were a snowy mountain there could even be skiing, sledding, snowboarding, and other wintery sports. Just a random thought I had to create an epic gaming experience unique from the beachy plaza we have now!
But like honestly tho as much as I understand where you’re coming from, there isn’t gonna be a new plaza anytime soon. There is a bunch of improvements coming to the plaza soon, as well as other features within the realm of your suggestions, however the Plaza itself isn’t getting a massive redesign again for a while, at the very least.
You are, however, welcome to make a mountain/campsite Plaza of your desires if you so choose by building one in the Smooth Autumn Condo, so when Community Condos drop, you can share your Camping Plaza with the world.