BTB games often start without being a full game now.
https://www.halowaypoint.com/en-us/news/big-team-battle-refresh-2019
Meander, Panic Attack, Voyager, Ancestor, Boulevard, Fracture, Guillotine, Port Authority, Scavenger, Traffic Jam should all be removed. I like most of these maps but some of them just look bad like Port Authority, Traffic Jam , Guillotine and Fracture. Big maps with open world out door areas are my favorite for BTB.
There are so many Forge maps, it shouldn't take much time for the devs to add 10 new maps in a rotation every 3 or 4 months, then replacing the 10 new ones they add with 10 other new ones. (but keeping Viking, Dead Heat, Dispelled, Crossbow, Fossil, Hinterlands, Pioneer, Echos and Entombed)
They should also add more maps for Big Team Super Fiesta but it should be a different set of 10 maps, not the same ones added to the regular BTB playlist.