Whatever the intentions of any party the result is a OSS codebase splitting in two because they don't agree on the future of the project. That is exactly what is supposed to happen when that problem arises.
[0] As in "developers using the CMS"; for actual users of projects based on the CMS, absolutely nothing changes.
Calling this a hostile takeover is being extremely overdramatic. There was a fork.
That being said, it is the right of the maintainers to fork the software as allowed by the Open Source license the original code was under. Users now have the choice of paying the original company or using the free version with a new name. I fail to see how this is user-hostile.