I don't see many usecases for that - besides the cable length problem mentioned in the article, it would have the effect of reducing choice for the consumer.

I could perhaps see displays including a very basic GPU and advertising it as a plug & play display, no need to check if your video card has enough ports, but I believe (citation needed) multiple display outputs have been standard for years now.

If that's the usecase you're after, I'd also suggest that you're better served by USB - there have been basic USB external GPUs available for years now that would do the trick.

This doesn't seem to be a popular idea but I think it makes a lot of sense. The issue with the idea is that you're now halfway there to an all-in-one, and I think manufacturers will just keep adding components until they get there because theres way more consumer demand for that.