If that really is the Sender Address, and has not been spoofed - I’d have to parse the message’s Internet Headers in order to be sure - it is likely to be legitimate, as sell.amazon.com is indeed a valid Sub-Domain that Amazon - and various of its far-flung teams, subsidiary & associate entities, etc. - use with a great deal of frequency.

In any event, it seems to smack of something similar which appeared earlier this week, and was investigated for legitimacy by one of the helpful Community Managers of the FMT (“Forum Moderation Team”), @Sandy_Amazon; Sandy confirmed the legitimacy of said similarly-seeming “sketchy” message in these two posts:

https://sellercentral.amazon.com/forums/t/is-this-a-phishing-email/1473036/8

https://sellercentral.amazon.com/forums/t/amazons-seller-advisory-board-such-a-thing/1473344/3

It is my current understanding, gleaned from information sources other than the ASF (“Amazon Seller Forums”), that the Amazon Vendor Summit is indeed a planned event; if so, I would not think it unreasonable to conclude that it and the Seller Advisory Board are part and parcel of the same Amazon Initiative…