That's not very OSHW if you ask me. I'd rather an unaccelerated framebuffer, or even no graphics at all.
They don't seem to understand what kind of market there is for this sort of device. If I didn't care about this sort of thing, I would just grab one of the many proprietary-encumbered SBCs, any of which faster and cheaper than this board is going to be.
That's one of the neat things about how programmable their cores are; you can resolve in the tile to just about any surface format since it's all done in software anyway, so it's really easy to integrate with other scan IP blocks.
TL;DR: You'll probably get a simple un-accelerated framebuffer (maybe with a few planes) with a PowerVR off to the side that you can just ignore if you want.
The problem is that I can't, and most people who care about freedom and thus could be interested in a slower, more expensive board... can't either.
If it's a separate chip, that's better, because I can cut power to it, or outright desolder it.
Still, I'd be uncomfortable having paid for a chip I did not want. Much like being forced to pay for Windows when buying a laptop to run netbsd on.
My point, if you missed it, is that this is not the sort of purchasing experience those who'll pay extra coin for a board with a slower chip that's also less power efficient just because it's more open would actually desire. And thus, it is not sensible to include such a chip.