You now respawn at the last save point you tripped. Since every boss has a save point nearby, if you don’t get the drop you want, you simply need to quit the game and then start it up again, and you will be right by the boss again.
I could be very wrong on this but this new spawn point system is not a new feature in BL3,I’d Guess from memory recall TPS had much better spawn points very similer to this due to you having to recharge you’re o2 while in zero gravity,Also certain bosses in BL2 had closer spawn points for example Pyro Pete.
If they let you designate your spawn point that would be new. Respawning at the last one you tripped has always been in game. It sounds like they just rethought the placement of them to be more convenient.