While I think this is a nice thought in theory, it is actually one that would cause a lot of issues. One of them being, as stated earlier, that players could be falsely kicked. This would happen due to players being next to each other or in the premise of those blocks. Also what @jollow250 said is very true since some fights can last a long time. It would make it very hard for this to be coded and incorporated into the server. I am sorry, but even seeing this suggested now after seeing it previous, I still am not for this idea being added since I see more cons then pros for it.