There is a fine line between delaying and playing as a team.
Also +3 gear/skill/classes arent taken into account when teams are balanced by banner, so with or without this idea players with +3 are always advantaged, as are players exploiting their classes to their full extent.
Even today, you have people who delay as much as they can.
In most games I've played where there is a difference between dying and living (without regards to your team winning or not), people "fear" dying thus think more before putting their lives in danger. Most of the time it means they will play within a group to increase their chances.
The opposite side will do the same, thus there will be no overall increase in delaying, just more group fighting.
I sincerely think this idea is genius.
XP barn was problematic for people wanting to level up.
This "no repair if you survived the round" thingie will finally put a very good reason behind the upkeep system
Also its kinda realistic that if you didnt die, what you are wearing didnt break as bad as someone who got chopped up. Maybe just lower the repair chance by half if you survived? Either way it will be incentive enough for people to mind their own team.