No. Years back, I grew a naked-seeded pumpkin (Streaker Jack) that was impure; one of the plants turned out to have hulled seed. I had (unknowingly) used male flowers from the hulled plant to hand pollinate some of the others in the row, and when harvested, the seed from those plants was still hull-less. Since I liked the quality of the good seed, I wanted to try growing it again... but the vendor had dropped it, probably due to other complaints. :-(

I've grown Kakai as part of a 4-variety trial of hull-less pumpkins, and the seed was large & high quality. The yield was somewhat temperamental, though, and it had problems with seed sprouting inside. If you grow it, I would recommend opening the pumpkins as soon as possible after they are fully ripe.

There is another hull-less variety that I received in trade several years ago that has a high yield & does not sprout, but it also had a hulled impurity... I hope to select a pure hull-less strain from it in a few years.