ND tried it back then with U3+TLOU, but weren't able to keep two big full productions at the same time, so decided to focus again on a single big project at the same time again after the U3+TLOU:
https://www.videogameschronicle.com...ll-struggling-with-multi-project-development/
So they had since then a single big project under production at the same time (first Uncharted 4, later TLOU2 and later TLOU Online) while they had other projects in preproduction or were minor projects like overviewing/supporting the remasters/remakes/ports.
It has been recently where in addition to TLOU Online they also have a big SP project under production after having growing during a few years.
SSM only worked on a single big project at the same time. If the Cory new IP pitch got approved in summer 2018 and entered preproduction, so production pretty likely in 2019 then it would be the first time (I assume it's the case) that would be the first time they have two big games at the same time (I assume that the GoWR after release moved to start the production of the next GoW game, which I assume was under production until then also overviewed by Cory).
Bend, Media Molecule, Polyphony, Housemarque, Bluepoint, London, Sucker Punch, San Diego also worked always in a single big project, and same goes with Guerrilla, who recently with HFW+Horizon Online (if they mostly develop it instead of only overviewing/supporting other studio, as they did with Horizon CoM) and later H3+Horizon Online would be the first time they work on two big productions at the same time. We don't know about Sucker Punch, but they may also have switched in recent years to have two full production teams.
All these teams had only a single full production team and in recent years thanks to the growth in manpower some of them created a 2nd track for full big AAA production. Some who didn't make the jump to have a 2nd big project may do it.
Insomniac, Firesprite, Bungie, XDEV, Japan Studio (now splitted into Asobi and the Asian XDEV team) already worked on multiple games at the same time before but they kept growing, so pretty likely now will handle more games at the same time. If not now in the next few years pretty likely will start to do it.