They wont add any extra mods to any of their servers because then people that dont have the mym launcher couldnt join.
Veinminer isnt a main mod and its just a setting in the server if you can use it and you can still join whitout
its still not going to happen though, if the pack was intended to have it , it would already be in it.
Mym will not add mods that are not already in the pack. If they did that, some people who wanted to play on the server, couldn't and Veinminer is a Mod not a setting.
id liek to point out taht skyfactory should have veinminer and in fact ive played it with it but on MYM its been removed so maybe blaming the pack or sayign the pack wont be changed isnt the issue.
Again if it's intended to be in there then the modpack author would have added it Please contact them.