The latter already happened[1]. Bayer offloaded most of it's ag business (to BASF) and replaced it with Monsanto. Monsanto has been rebranded "Bayer Crop Science". Although I'm guessing much for the same reason, Monsanto never rebranded any of the dozens of seed companies it acquired over the years (e.g. Dekalb, Seminis, Asgrow, etc.)
The same also goes for Charter → Spectrum.
>Monsanto has been rebranded "Bayer Crop Science"
When the company that commercialized heroin and was complicit in the holocaust is a better brand you really got a PR problem.
Maybe Microsoft's reputation is exactly the reason why it was left out of this announcement.
Sometimes a brand is so tarnished that the owner tries to hide it from the people who hate it. (For example, Comcast → Xfinity. I expect Monsanto to go the same way and become Bayer.)