The idea is good, but playing with randoms the implement would be flawed. Much like the leaver penalty they have good intentions, but literally miss the mark on everything they try to fix or make better.
If you were to get a reward for re-spawning a boxed player and seeing the enviroment in the game today here is the scenario you will see played out.
You get downed in a ranked game, and as it is now this next part happens frequently anyways. Your "teammates" loot around you and wait for you to die. They then grab your card loot your box for anything they wanted that you have. Then they might re-spawn you. With an incentive to re-spawn you like what you are suggesting the only thing that will change is now they have an incentive to re-spawn you, great they get RP for doing that. Means they can run to a beacon and as soon as you are called in they have hiked halfway across the map.
Honestly I get your intentions I really do, if more randoms played like you are describing it would be a great idea. If you haven't had the joy of a teammate teabagging you, fake rezzing you then count yourself lucky. Because i have seen that plenty of times. Or the guy who plays as octane running away from a fight cowering in a building waiting until the enemy moves on rushes in and grabs revive cards only to go hole up in another hiding spot for the duration of the game to get blasted by a full squad because he is too chicken to re-spawn his teammates.
Honestly my point is in a situation where you have decent players your idea is a good one, but for the community as a whole with the players i have seen recently it would reward straight up crappy players extra RP for being crappy teammates in the first place. Oh I get extra RP for re-spawn, well i am gonna let you die for the chance to re-spawn for extra RP.
The better idea in my opinion is remove the killcap, Fortnite certainly didn't have that during it's tournaments the more kills you got the more coins you got pretty basic stuff.
In the end the ranked system is broken AF, it is not skill based in any sense of the word. If you are lucky and play with the same 3 guys every time then it is based on your group dynamic moreso than any skill. That is one of the reasons so many people asked for solo ranked. I too would like ot find out where I am in my skill, not based on someone else's skill and ability to down their targets.
Back to your point at hand all things being equal if you have decent teams then yes this a good idea, but as long as the lobby is stacked the way it is it would just lead to more griefing for "easy" RP. Much like camping was the meta for last season.