IMO it is not a bow, firearm, or muzzleloader. I think some people get too hung up on what a tool like this is classified as. Create a "Airbow" season; and so what if it overlaps with archery, muzzy, and/or firearms season.
Resident adults in Pa. are all given equal opportunities to buy licenses, buy bonus tags, and hunt multiple seasons. A hunter can choose to fill their tag using a long bow, recurve bow, compound bow, crossbow, inline ML, handgun, single shot rifle, bolt rifle, pump rifle, lever rifle, traditional ML, or in the future a semi rifle and airbow. Why does it matter to anyone else what others choose to use?
Good luck, Tony