

Do you think IBM wouldn’t make Red Hat completely proprietary if they had the chance?
No. I don’t. For quite a few reasons.
1 - Red Hat has released new software (quite a lot actually) that they wrote, as GPL since the IBM purchase (rather directly refuting your thought experiment)
2 - A huge amount of Red Hat Enterprise Linux is permissively licensed. They have the chance every day to make this proprietary. They don’t. Again, answering your question.
3 - Red Hat is one of the most profitable parts of IBM.
4 - IBM has left the Product and Engineering teams independent. Because of #3 obviously.
5 - I use facts when forming my opinions
Red Hat is the most commercially successful Open Source company and perhaps the biggest proponent and prolific author of GPL software. They founded (created on purpose) one of the most successful community Linux distributions (Fedora)—a distribution with annoying dedication to free software (eg. codecs). Many of the “leaders” and “contributors” to Fedora are Red Hat employees. Red Hat of course does not make Fedora proprietary since having it be “community” led is a core part of their strategy.
Finally, you do not have to fear a Red Hat take over. Because it already happened.
Half the software (source code) you think of as GNU sits on servers Red Hat manages and controls. This is where that software is developed (not in Savannah—which is just a mirror). I am talking about GCC, Glibc, core utils. Etc.
Do you use systemd, pipewire, Wayland, Mesa, Podman, Cockpit, or Flatpak? Where did all this software come from? From the Free Software Foundation? University students? No, these are all part of the “Linux platform” as defined by Red Hat and they have swept us all along with them as they create it. You can probably add GNOME and GTK to the list at this point.
Has Debian moved to all these technologies? Why? Because of the FSF? No. Because of Red Hat.
Personally, I am ok with it. My core distro uses A LOT of software brought to me by Red Hat and I am thankful for it. But I avoid a lot of Red Hat software like GCC, Glibc, and systemd. But the replacements I use are also mostly corporately funded (Clang, MUSL, and dinit).
Adding to this, Google created Android, wrote all the source code, and released it as Open Source.
By definition, Google cannot take anything here. It is only a question of what they give way in the future.
What Google wants is for people to use Google services. So they are making that less and less optional. There is no way for them to mandate this in Open Source and so they are shrinking the size of AOSP.
Online “services” are the greatest threat to software freedom. What kind of license is used has little to do with it.
Since this is a “GPL saves the world” thread, how would the GPL change anything? Android is mostly permissively licensed. But let’s assume that it is all GPL. Since we are talking about code Google wrote, nothing changes at all.
And the Linux kernel is already GPL licensed. Does that mean I can run whatever I want on my phone?
No. The threats to freedom in the Android space have literally nothing to do with permissive vs copyleft.