No I unsubscribed and restarted the game. I don't usually play custom games, but I wanted to test out the commander and low and behold the changes from the newest patch haven't been fully implemented there I guess. Everything was working fine in automatch though.
I'd recommend double checking to make sure it isn't selected in the match settings. I just tried now and the t4 truck was 105 fuel with the mod enabled in match settings, and 120 without it.
Edit: Just checked and the goliath will not show up if you have the mod enabled. You can change it by going to Options -> Tuning Pack in the custom game screen.
No I bought it, but I did just test it in automatch and I could build the Goliath(so could the random OKW player I was matched with). So it is only in custom games; also the fuel for the Schwer truck is 105 in custom games and not 120 like in automatch.
Do you still have the December balance preview mod selected in custom games?