The kitten is too young to know for sure what look alike he is. But he is a point ("siamese-mix") for sure. I presume Maine Coons can be pointed, esp if not purebred, but MCO arent known to be points. Think on him as a Ragdoll look alike till you know for more sure.
The kitten seems pretty young to be sold. Im not even sure its 8 weeks which is a traditional minimum - 6 weeks perhaps?
Did you buy the kitten from a professional breeder and did it come with papers? Without papers he or she is not a pedigreed cat and this would be what is known as a backyard breeder. As Stefan said, they probably sold you the kitten at a very young age, so it's hard to tell for sure how closely this kitten will end up resembling a Maine Coon.
Either way, it's a beautiful kitten
I would discourage others from buying from a backyard breeder but I hope you enjoy your new addition to your family and please stick around and let us know more about him or her.