Cool idea that is very unlikely to be made.
As an add-on, probably not (it would require a lot of effort) but as a third party software, it’s already possible (I invite you to read my previous comment).
2- It have to be offline
ad 2. It just had to. Thats Bender principle it dont require you to have internet. So every online voice recognition like Google, Cortana, Amazon, Siri is off the table.
Things seem to change (about this “strict offline principle”): take a look at the “Blender and internet” paragraph written by Ton Roosendaal: https://code.blender.org/2021/10/blender-3-x-roadmap/
3- It had to be GPL compliant
ad 3. Blenders is GPL so it legally requires to have all libraries to be GPL compliant
Not necessarly. Some Blender add-ons (UVPack Master 2 Pro, Exoside Quad Remesher) are based on two parts:
- a small script (under GPL license) that acts like a bridge between Blender and a library / binary.
- the real core of the addon: the library or binary (.exe) which itself can be a closed source file.
4- had to be free
ad 4. Blender is Free and every Blender feature have to be free
The GPL licence clearly allows softwares (or add-ons) that are published under this licence to be sold. Example: commercial Blender add-ons.
It is also allowed to fork Blender, modify the source code and sell it under another brandname: Example: https://blendermarket.com/products/k-cycles
In fact, it’s not the add-on itself that is being sold but the download service and support. But yes, the source code of a GPL program has to be free.
There have to be someone to develop it
ad 6. There is lack of developers even for current scope of projects eg UV, texturing so it had to be someone from outside of BlenderDevelopers, and not unded from fund