Microsoft isn't funding UNI. Communication Workers of America, which is working to unionize Microsoft employees, is. They're on opposing sides. CWA recently go

Microsoft isn't funding UNI. Communication Workers of America, which is working to unionize Microsoft employees, is. They're on opposing sides. CWA recently got Microsoft to agree to be neutral on whether Activision Blizzard employees join a union after the acquisition closes. This was a big win for CWA. It's likely that CWA doesn't want to risk this agreement by attacking Microsoft on an unrelated issue. It sounds like UNI was only interested in funding this report in order to use it in their fight against Amazon. When they found out it might create other problems for them, they got cold feet.