Apart from fixing the lag and host migrations that you've had two years to sort but hubris led you to not actually spend a second fixing...

Remove pointless playlists like Cell vs Rebel, Maximum FFA/TDM and Developer's Choice and add a Mercenary TDM mode.

Squads are turning your audience off massively as new players are stomped. Put in a TDM mode where people can only play as individuals and the sides are balanced each round based on how people scored in the last one. It's a proven solution.

I imagine the retention rate for new players is horrible right now. This should have been in at the start and is a glaringly obvious solution. But what do I know? I'm not the genius developer of a FPS that has literally hundreds of people playing a month after launch!

FFA
TDM
Merc TDM
Spears/Crash
Extraction/Relay
Hunter

That's all you need. Easiest way to not facture the playerbase further and keep new players from getting destroyed and turned off.

This game is circling the drain. Unless bold action is taken, it'll be dead within a month.