This is hardly a matter of being "trumped"
The existing Buffs are so beyond it, the military can barely keep three of the six flying just for the west coast. The rest of the country is covered by 40-year-old + Hercs and again, there aren't enough left flying to do the job properly. As for 50 being in service, only three are actually being used for search and rescue - in Canada - as part of the world's oldest search and rescue air fleet.
Now Viking wants to put Canadians at further risk, by trying to get the government to buy a plane that doesn't even exist, and if they can build, it, certify it and demonstrate that it might only do part of the job. They also want Canada to buy Dash-8's for the rest of the country - a plane that has no rear ramp and couldn't do the job of a 40-year-old Herc, let alone the new requirements that might be laid out by the government.
The C-27J is available today, without modifications, without need for recertification and could no doubt be ready to save the lives of Canadians years ahead of anything Viking could offer and can handily do the job required anywhere in the country with a single plane instead of a patchwork fleet.