Things just got clarified, so probably this was a missunderstanding of the GPL, and Mathieu will need some time to adjust things to comply with the GPL requirements.
@xan2622 I saw your question in Blender Artists and I want to punctualize one thing:
We should always have in mind two situations:
1.- The source code is packed or provided together with the binary, so you download the zip file form the fork and it includes the source, or you download the zip file from the fork and you also have a second zip with the source available.
In that case only the persons that have direct access to the binary have access to the source code, and if they share the binary with anyone, they are responsibles of giving the binary together with the source code.
That’s usually uncomfortable because at each release you will ahve to pack and upload the whole source code again and again, so the most comfy way of sharing the source code is the second one:
2.- You provide a written offer on how to get the source code, for example you explain that the source code is available on github.
In this case since the original receiver don’t have the source code directly provided together with the binary, what that receiver has is a written offer with the explanation, and when that user (A) shares the binary with another user (B), he must provide B with the written offer.
Then B, without being a customer of D (developer) can go to D and ask for the source code or download it as explained in the written offer.
So the source code is not only available to customers of D, but to any binary user, that can be a customer of D or not, and depending on how the binary was distributed the responsibility of providing such source code relies on D or A 