I should point out that the Rocket Lake rumor suggests there will be a 14 nm IGP chiplet along with a 10 nm version although it's possible that the 14 nm one is just Gen 9.5.
I guess that would open up the possibility that the first dGPUs are actually on Intel 14, but that would be tough to be competitive.
I don't think it'd be that tough. I'd guess the Intel's 14nm is better than TSMC's 12nm and its not like Turing is garbage. Honestly, if Intel hits Pascal levels of efficiency and its large enough (to be able to offer good performance levels) and a solid price (say they release a 1080Ti performing chip for $300-400), with maybe some interesting features (like a cutting edge video processing block, maybe some ray tracing capabilities or ability to handle more displays or higher res displays - so say it can manage 8+ 1080p displays off a single card or multiple 8K displays), it could be a decent alternative for quite a few people.
I wouldn't be surprised at all for Intel to be
very aggressive on pricing when they first come out just to try and gain marketshare, with them being very strict about market segmentation (pro vs consumer, tiers of chips; actually I could see them offering efficiency focused ones that can't overclock and then enthusiast ones, much like they do in CPUs). I also expect they'll push form factors (they already have the NUCs, and a leg up in laptops and probably all-in-on PCs).
Something that will be really interesting and a potential measuring stick is if Apple brings out any Intel CPU+GPU devices.