Yes, but the rules do not give the difficulty of a commission roll.
If this roll is meant to be universal across all "commissionable careers", then the section on Commission should say something along the lines of "The commission roll is SOC 8+ (Average)." If indeed it is actually an "Average Difficulty" to get a commission in the given service. (Traditionally in other Traveller versions it's not, but it does seem that MgT v1 had all the commission rolls the same.) I'd like to see commissions listed in their career spread (as they were in v1), as I think time spent flipping back to previous pages for reminders is undesirable.
It's also worth mentioning that "Checks" are not discussed until Chapter Two, so assuming the new player will naturally know to turn to Chapter 2 to figure out how to make a "Commission Roll" is perhaps not wise.