You're right that "gimmicky" maps are more stale than standard maps but considering the vast majority of maps we have are standard maps I think it's a good thing to have some maps that have basically their own meta players have to adapt to.
Let's see it this way: if we have 5 standard and 2 weird maps in the mappool the overall variety is higher than when we have 7 standard maps even if the weird maps are more stale on their own.
The only problem is of course is that there's always the risk that a map turns out to be horribly imbalanced.
Isn't that pretty much what we have had the past few seasons? But what ends up happening is that the pro players end up vetoing the same weird maps over & over, so as a result we see the same few maps over & over again?
This "added variety" that you speak of ends up having the opposite effect where we in practice have less variety due to players vetoing those weird maps.
The key imo is not to have weird maps, but to have good maps with unique features.
I've been of the opinion that some of these more unique maps we've seen in the pool simply aren't that good.
I'm generalizing of course but I think map makers need to respect the plot. That these maps need to be balanced because this game & even our pro players livelihoods depend on them.
Given the past submissions I have no doubt our map making community will be up to the challenge. Its that selection process by Blizzard after the fact that i hold my breath for. Looking forward to seeing what everyone comes up with