MTS first class was 1986.
It isn't a "rule" about not getting married, its worse then that, it is a "suggestion". That gives the Service Dept all the leeway they need to get these guys off the "program" or keep them.
"Program" you ask? Yup, MTS brothers with an assignment get correspondence from the branch at least once a year or more. A "Personal Qualifications Form" is filled out yearly by the CO which basically tells the Service Dept if the guy is "company material" or not.
If an MTS grad dates and gets married, it is up to the CO and his recommendation as to whether he stays in the program. Who he picks as a wife (i.e. is she a pioneer with a good reputation) matters mightily.
Once married and if approved to stay in the program, you can be reasonably sure that they are at least keeping a long term view of this new "super couple" as possible CO's. The current CO has to recommend them, the DO then signs off on it, then another "Personal Qualifications Form" is filled out by the local elders on both MTS grad AND his wife.... They are then approved as subs. Once you are a sub-CO couple, and esp if he is an MTS grad, it is usually only a matter of time before they become CO's....