We actually don't have anything to do with the MUL. I'd suggest you ask in the Ask the Lead Developers section.
My answer is always going to be your game your decision.
I was asking here because I am running a Mekwars Server. :) I did use the Master Unit List for the buildtables but with Production and Availability. I have to say, taking a step back and looking at all the factions... FWL, DC, FS, WoB, Crusader Clans, Warden Clans.. each faction does have its own feel to it. I had two players asking for older units, so I wanted to see how other people are using the Master Unit List.