Well, any new product will come with the warranty card. Whether the manufacturer accepts is valid depends on if the seller is authorized or not, and that will be determined by the seller ID on the invoice. I would only trust what AT has to say about it, not the seller. I doubt they are fakes (though I did a get a fake Xaomi Piston IEM from an amazon seller), but even if authentic AT won't warranty them unless its an authorized seller. AT has had some problems with counterfeits, as many manufacturers do.
BTW, why the heck does that seller go by so many different names? That in itself would bother me. Its not a gigantic investment though so if they sound good and no obvious identifiers as non-authentic, you probably are fine. These phones are tough, and I doubt you would need the warranty anyway. As long as you understand the risk.
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