pretty sure that's the partly the motivation behind the acquisition

Probably in the long term. Over the next years, the technology is not likely to be ready for the number of customers a wholefoods can have.

But the stores should work well as distribution centers for grocery (and other) deliveries.

Yep it will take a while. But it's a faster and less risky route to market than Amazon branded brick and mortar grocery stores from scratch. And many other synergies like you say