Another variation of rules is that once a CPL/IR (+MCC on Integrated courses) is applied for/issued, the ATO responsibility ends. The fATPL holder (once MCC completed) completes the type rating.
With MPL customers, the MPL licence is issued once the type rating (standard issue) is completed, and it is at this point the ATO responsibility ends. They have oversight of the type rating course. Incidentally the TRI/TRE need to be MPL qualified as well, irrespective that the type course is the same for all.
Line training now takes place, and invariably the MPL FO will shine as the 120 hours of simulator prior to the type rating course has been using the specific SOPs of the company.
The ideal course for those who wish to spent their career in the airlines.