That is not that “might” work, that’s one of the situations that actually work.
In the license they talk about “intimate communication” as the thing that makes the apps to be considered as a single app, and that means sharing memory, at least sharing complex data structures in memory, something specific from Blender to a closed source app.
Other solution is to use a “bridge” that is compatible with closed source, that part of the app, the bridge, must be open source and licensed under a compatible license that won’t be affected by the GPL, Apache or MIT, and that’s the part that can communicate with the GPL app, then that part must modify the data into something different that will be then communicated through memory to the closed source app, but it must not be the same data structure that was generated in the original app.
There are many ways to mix closed and GPL open source, devs must work a bit more but they also have to stop complaining because things are not as easy as with the Autodesk SDK, where the effort is put by the users by giving their privacy to Autodesk.
And I still read some questions about “what if… blender goes behind a paywall under some weird situation like a full rewrite…” well… have any of you, that fear this so much, wrote to Ton and asked him directly about this possibility and the envisioned future for Blender? and about what he meant with the business part and all those things?
I understand no one asks to any Autodesk responsible person because they simply won’t answer or will answer with the “we are a publicly traded company and we cannot speak about the future”, but you can write Ton whenever you want and ask all this. As I said before, please make the answer public