Currently, the limit of the number of players inside a server is 127.

It would be cool that the limit could be increased.

In Arma 3, the limit of 127 was because you can only have 127 groups on the same side, maybe it's related. After some times this limit has been increased to 256 in Arma 3

It's designed only for total conversions mod that wants to go over this number of players for sure.