I have bought many, many, many (yeah, I mean many) items on Massdrop, almost all audio gear.
Yeah, some of what they sell comes with no warranty (just 30 day return if defective), some with just a Massdrop warranty (up to a year), and some with the original manufacturer’s warranty. Depends on the item. I am not sure how they choose what they sell w/o a warranty - if they are a channel from the manufacturer to sell off excess capacity at a discount (saving warranty cost), or if they are not authorized sellers, etc., but I am pretty sure their warranty approach is one of the reasons they offer some of their deep discounts.
I have been lucky, only had an issue with one item from them. Of course it was an item without warranty coverage. Personally I have no issue buying from Massdrop and trading risk of not having warranty coverage for deep discounts.
Now, those delivery times...