“Parker” is a brand name, and they make a variety of shotguns. As was the case with those other firearms you mentioned, some of them are available in large calibres that exceed 10,000 joules of energy. Those versions would be prohibited.
In the case of the Parker, which is a shotgun, it's more likely that the shotgun would be available in 8 gauge. With a barrel of that size, it would exceed 20 millimetres and be prohibited for that reason.
However, Parker shotguns that are chambered for ordinary hunting calibres—like 10 gauge, 12 gauge or 20 gauge, etc.—would be unaffected and would remain non-restricted.