The Blender foundation owns and controls the distribution of Blender under the Blender “brand”, including the trademarks and the services offered through blender.org and subsidiaries. Call that “official” if you will, but it really comes down to the brand, not “the code” and not “the software”.
Now, consider the fact that most Linux distributions build their own versions of Blender, perhaps with their own modifications on top. There could be a trademark dispute here, like with Firefox and Debian, who chose to rebrand Firefox as “Iceweasel” for a while. In practice, there usually isn’t, because there’s no conflict of interest.
“The software” or “the code” is a bit more amorphous. Technically, nothing stops a gang of rogue Blender developers from creating a fork of Blender, let’s call it “Shredder”. They’ll take all of the code of Blender, plus some amazing features they added through their elite coding skills. They take full creative direction. This program turns out so successful, the “official” Blender is abandoned and they get all the moneys. Waving the white flag, the Blender Foundation chooses the “Shredder” codebase to be the new Blender and instates the rogue developers as the new leadership.
Scenarios like this have played out multiple times with FOSS projects, due to conflicts of interests, leadership issues, disagreements of direction, and so on. Ultimately, the brand doesn’t really matter. The “official” part doesn’t really matter. The software matters. Almost nobody uses OpenOffice anymore, for instance.