Just like cadets today, getting a MPL will just be another avenue into the airlines for those that want to go that way. I suspect though that MPL’s will replace the traditional cadet training schemes that exist today. For those airlines that currently pay for their cadets training, if it is cheaper they will jump at it.
If you have or are going to go the GA, Military route I wouldn’t worry too much. They will continue to employ from as large a cross-section of the aviation community as they can to keep supply in check with demand and hence pressure on terms & conditions.