The average FOSS dev doesn’t have a lot new to worry about here, IMO. GitHub wasn’t ever a not-for-profit, people were already worried about over-centralisation.
However GCE, IBM, Oracle and other small cloud providers should be very worried. The entire “MS ❤️ OSS” strategy has been about driving Azure adoption. Every foothold they gain in the ecosystem will be used to steer towards that. Bad news for cloud competition.
Naturally less competition is worse for consumers too, I should add.