I feel "stealing your community" is lawyer hyperbole, but people also seem ok with what MS is doing with copilot, and I am not.
If you think what copilot is doing is ok, and there is nothing wrong with it, I'd love it if you could go through this small thought exercise, and see if it impacts your view at all:
Say you write a bunch of code, and release it under GPL. For the sake of argument imagine it is something complicated that you care about.
Now say another person is trying to do what your code does, and they find your code, a say "excellent". They then copy and paste it into their project, and release their code under a BSD license instead.
Would you consider this theft of your IP? The law certainly would, and I think most devs would as well.
What would you say if they instead release "their" code as public domain?
Now we'll go a bit further. Another person is trying to solve this problem in some commercial software. They find your code, copy-paste it into their project, then sell their software and don't release the source, or even acknowledge you.
Would you consider _this_ theft? again the law would.
Now, what if instead they found your code through the invalid BSD relicense? or the invalid public domain one?
To me every one of these would be theft, and every one would be required to required to release the source of projects that made use of my GPL'd code, under the GPL. That is literally the whole point of the GPL.
But let's imagine a different route.
A person is writing some code and can't work out how to solve a problem, so they ask on StackOverflow. Now another person comes along and answer the question by copy-pasting from your project into SO. The first person says "yay!" and then copies that code, and we repeat the above scenarios.
In an even more extreme case, imagine both of the above people work at the same large company - so neither knows or is even aware of the other - how does this impact what is going on? It's two people, but fundamentally the company is copying the original GPL code into SO, then copying it from SO into its proprietary code.
I get that MS and GitHub try to position it as if copilot is "creating code", but it is simply doing a statistical code completion that is demonstrably happy to copy and paste from the original source into the recipient code. To my mind all it is doing is providing a mechanism to launder GPL (or whatever) code into your own without the license, by slapping "ML" and "AI" on the process and requiring more than 3 keys to be involved.