This will not primarily be for rescue ops. This will be for supporting Marine standin operations on and within the first island chain. The marines have been trying to figure out how they can handle sustainment and logistics in that environment.
You can read some wonkish article about this (back in 2022) https://warontherocks.com/2022/09/sustainment-of-the-stand-i... . You'll note that the article does suggest revisiting seaplanes as a distribution option.
With a few hundred miles range, these craft would be suitable as one way island to island hoppers, or 2 way over the horizon ship to shore transports. For a sense of scale, its ~140 miles from Luzon to Scarborough Shoal (one of the contested islands in the South China Sea).
The "Viceroy" craft that Regent has mocked up on their website claims 180 mile range, 3500lb of cargo / 2 crew + 12 passengers.
EDIT: And to be clear, the article title says "to get", but the article makes clear, this is basically a testing and development contract. There's no certainty that the Marines will get this capability in any meaningful way. Probably better to replace with "to test". This is particularly important because the commercial version of this craft is also still in development and testing.