I've noticed a lot that there are a lot of people who aren't able to make it into a match because they need more than 20 secs to load in. My recommendation is to try to lower load times or to extend the time that people are able to spawn in after loading into the server. I've played several matches where the very first objective pretty much had to be taken by a lone shooter. If you've got an SSD, you're ok. But rip to anyone with an HDD unless this is addressed.
We can't put faster harddrives into players PCs nor we want to stall match because of such players. Matchmaking is waiting for players to load in before it starts pre-game timer.
There are issues that some players won't be picked up by initial spawn wave or will be put into a "spectator" team instead, these issues are under investigation are are being fixed right now.
I've been assuming that some of the delay is also new players taking some time to choose gear and explore the loadout options. Even as an experienced player if I'm experimenting with new options or checking out how a patch effected what's available I will hit deploy a while after everyone has loaded in.
In coop if I'm the first one in I'll usually hang around the truck for a while until more of the team is there. I've had a few times where a coop game has been lost while I'm still in the loadout screen because one or two players decided to rambo the first objective by themselves.
I think the solution is, come up with a generally accepted amount of time to pick a loadout. Then make it so pregame lasts until all players connected and see loadout screen, and then starts the timer when all players have had the chance to gear up.
Why try to guess what the load times are, when you can just account for the difference?
Or, even better, give a grace period for people to spawn if they missed the initial wave. There is no valid gameplay reason to force players to spectate for several minutes at the beginning of their game, simply because they missed an arbitrary menu timer.