If the Microsoft development team were to get turned loose on Adobe software, it would destroy creative software as we know it.
If MS was to buy Adobe, I do believe that they would operate it as a separate entity and not bring it directly under the MS fold. That would just be setting their money on fire by doing that.
They can even get the updates/changes of their flagship software (of what used to be their flagship software), how do they think they'll be able to handle software that they bought and have to get used to the underlying code.
Microsoft Word, on the other hand, has changed drastically with each new release. I’ve been complaining about their “change for the sake of change” approach to software development for years now. Things as simple as constantly moving functions around to different drop down menus and changing the user interface have made MS Office products a pain to use. With each new version comes a learning curve that slows down workflow for even the most PC savvy users.
Thankfully, I have never had to deal with Word in that manner. I stopped with 2007 Office and never looked back. Now, it's not even available on the platform I use now.
I have had that situation though on much more expensive software. There was a good run of a 2 yr release cycle, but it took about 4 yrs on this last one. Always seemed to change. From simple thing like the UI color to the more complex menu items and the grouping of tools. Sometimes the tool symbols stayed the same, sometimes they changed up. There wasn't really any consistency there.
How would you like to relearn Illustrator and Photoshop once a year?
It wouldn't be that often. After all, as rolling of a release as CC is, they do still allow customers x-1 on versions. That'll give you an extra year to get comfortable (unless MS changes how many versions back one can be on, which is possible).