It also creates bigger questions about Amazon’s brand/trademark practices vis-a-vis forum selection where registration fees and criteria are minimal and rights are liberal.
Assuming it was successfully filed, actually returning the marketplace/reviews to OP would actually be more troubling…in other words Amazon would be willing to take the marketplace/reviews from a legitimate Trademark holder with an earlier filing date and give it to a legitimate Trademark holder with a later in time filing date from another jurisdiction.
Disclosure: I’m a lawyer and have actually represented a client that registered trademark A, sole the product on Amazon, then Amazon began selling a competing product with a similar (not identical spelling but pronounced the same) name they successfully trademarked B, ironically the USPTO rejected our clients trademark for C on the basis it was “to similar to B” whereas the USPTO never found B was similar to A. The difference between A and C being addition of a logo to the word mark.