Irrespective of how it may have been handled in the past, the M&M legal fine print is quite clear that miles can only be earned once one has at least applied for a M&M account:
Members can start earning miles after membership commences.(...) According to the procedure in Section 2.3.7, miles can be credited for a flight or a partner service qualifying for the earning of miles which takes place during the period between the submission of the application and the mileage account being opened.