The PC12 and C402 should have similar dirt runway capability. It’s a judgement call however when muddy. CapeAir can’t operate the PC12 because they operate under the stricter part 121 rules for Air Carriers that require twin engines. It’s a bad rule from 60 years ago that should be amended. I would take the PC12 over the old Cessna’s on any flight anywhere as a safer option. Its turboprop motor is bullet proof compared to the piston engines in the Cessna. The loss of a motor in the 402 often leads to a bad outcome and you have two that could fail.
CapeAir does have a C402 replacement aircraft ordered and they are getting deliveries but they are several years behind on the original delivery dates. They have now received 30 of the new Tecnam P2012’s and have 66 more on firm order. They currently operate 63 C402’s.