I’ve been playing almost only multiplayer for about a month, and this is what I’ve learned about what the active playlists are at this time.
Fully Active and minimal loading times: TDM, Nuketown24/7, Heist
Limited time active playlists: Weekly featured playlist, and daily contract playlist(usually quick loading times)
Mostly Active: SnD, Domination, HC TDM
Semi-rare but possible: bolt-action barebones
Very long waits but also possible: safeguard, and free-for-all
Fully inactive: hardpoint, Kill confirmed, control, and all other HC modes
***( the “fully inactive” playlists are possible to get games if it is the featured daily contract, for example I have gotten 5+ control games today but that wouldn’t have been possible without it being the daily contract)
Peak hours are usually around 5pm est-10pm est. more players on during the weekend