That's just a bet, I doubt Mozilla is willing to blast google on the chance there is someone willing to pay them, they'd probably rather have a sound financial cushion from non-google before going after google.

Microsoft just switched the rendering engine for Edge to Google's rendering engine, helping increase the monoculture.

Despite all Microsoft's posing and snuggling up to the Open Source world, they're just as bad as Google and Facebook if given the chance. (And they have been as bad in the past.)