A lot of the Brawls are random and bizzarre - They're fun here and there for a one off, but that's about it.
Others though change the dynamic of the battleground in a lot more interesting ways.
I really LOVE Frozen Arathi Basin, as it's so familiar but so feels so different at the same time. It's really a great spin on the original map.
What I would love to see is if Blizzard came up with 2-3 similar effects for each map, which alter game play slightly (but not in bonkers ways like Gravity Lapse). Imagine playing Deepwind Gorge or IOC in pitch black night, and no player can see beyond their own torch that they drop to the floor on combat.
Then for ALL battleground queues 20% of the time it would come up with one of these alternate versions of the battleground instead. I think this could could keep the battlegrounds fresh and a bit more interesting. Having a suprise weather condition kick in or similar would certainly liven up a random bg.