But while those imperatives are nothing new for many channel partners, they do weigh heavily on the industry.

"A lot of these suppliers are neutral in nature. They don’t particularly care whether they spend money on Amazon or Microsoft. There’s price parity," Wiedower said. "So if it becomes necessary to play ball with Walmart, I suspect a lot of these shops will simply spin up services on Azure and work from there."

Last week's blockbuster $13.7 billion deal for Whole Foods, which still needs regulatory approval, will likely harden the positions of Amazon's e-commerce competitors. "The full assault by Amazon on retail with the Whole Foods acquisition will definitely cause defections and avoidance of AWS by these factions," said Tom Kieffer, CEO of Virteva, a Microsoft partner based in Minneapolis.

With cloud Infrastructure-as-a-Service and Platform-as-a-Service increasingly commoditized, second-order rationales often drive buying decisions, Kieffer told CRN. "Boycotting AWS is definitely in this category," he said.

Those complex customer-supplier dynamics inevitably redound to the channel.

Walmart executives, like any other responsible corporate leaders feeling the "Amazon effect" on their retail businesses, "would push that sentiment onto partners," Trace3's Mellegaard told CRN.

Amazon's Whole Foods deal may benefit companies known to be big Google and Microsoft partners. One such partner, Tony Safoian, CEO of SADA Systems in Los Angeles, told CRN, "We're getting deals from this already!"

Webb, of Avionos, said in the past Walmart and other retailers, especially grocers, would encourage suppliers to use specific technologies to better integrate with their supply chains.

"For a long time, you saw Walmart driving technology innovation because they were looking to become more efficient," Webb said. "They needed vendors to make investments."

The anti-AWS phenomena is both an extension of that practice in which large retailers were "setting the rules of the game," Webb said, and "at the same time it's very different."

"What's probably the biggest difference, for the first time you're seeing an overlap where a broad-based technology service provider like Amazon is also becoming a very firm retail competitor," Webb said.

An AWS spokesperson told CRN that Amazon has "heard Walmart continues to try to bully their suppliers into not using AWS because they have an incorrect view that AWS is somehow supporting Amazon's retail business."

"Plenty of suppliers are standing up to Walmart and refusing to be told that they can't use the leading‎ infrastructure technology platform (AWS). Tactics like this are bad for business and customers and rarely carry the day," the spokesperson said via email.