It is against TOS but from what I have observed Amazon does not seem to be serious about enforcing it. Ebay got serious this year and either banned or suppressed them and now all of the retail dropshippers are moving over to Amazon because of this.
I see them on almost every listing - they are the ones with 50 - 80% feedback scores, with plenty of feedback describing customers having received items in walmart or home depot boxes, paying higher prices than what is on the receipts, as well as plenty of cancelled orders.
Retail dropshipping on Amazon is the “hot” business model for 2019. I expect Amazon to get serious about it a few months before Christmas. I never thought I would see the day when Ebay was ahead of Amazon in anything but they are schooling Amazon in a few areas now.