I agree with Blood, I'm going have to vote No. It should be not a griefable offense, therefore everyone has right to do so whatever they wish if they get a respawn coin. However, there is a good 50/50 chance that someone wants to respawn everyone, or not. Every respawn coins should have a kind of countdown, that usually respawns after the time has passed if no one got it. Someone can come back, and get it back. I do not see a problem with this.
Furthermore, what blood said is indeed right as there isn't a better alternative to pressing a button to respawn everyone. Sure, It's boring and unoriginal but having a respawn coin causes more issues aswell too.
If people don't like someone dropping respawn coin, well then I may aswell fake freerun and ruin everyone. Same thing
In the end I'm going have to vote No and everyone should advise new mappers, to not implement respawn coins.