Yeah I'm not sure they have yet, but if AMD can bring out a mobile APU it could be a huge winner. The Ryzen 3 2200G was excellent, and I'm sure the new Ryzen 3 3200G and Ryzen 5 3400G will be even better. It sounds like that's going to be a thing. Pretty sure Apple have been known to work much better with AMD than with Nvidia for many years anyway, so I wouldn't be surprised if within the next 12-18 months we saw MacBook Pros running AMD Ryzen APUs. Depends if they can eke out the same CPU performance as Intel's mobile CPUs while continuing to crush Intel's HD/Iris integrated GPUs.
There are already a number of high-powered gaming laptops running AMD Ryzen CPUs and more coming (just as an example, though it's using a discrete RX 580 GPU not integrated/APU) so I guess we'll see.
EDIT: I just wanted to clarify because my post was a little vague. AMD has been selling desktop processors they're calling APUs (Specifically the Ryzen 3 2200G) for a while now, and what you basically get is way better gaming performance than Intel processors using HD3000 or whatever. In fact for light gaming on 900p or lower with medium or lower detail, it basically renders discrete GPUs unnecessary, hence a lot of younger people with lower budgets using 2200Gs to play games like Fortnite on a PC.
AMD have announced mobile versions of these APUs. I don't know of any laptops that have released with them or been announced for them yet, but in theory - if the results are similar on laptops as they are on desktop PCs, you'd end up with significantly better graphical power in your laptop compared to an Intel-based system. And if that's the case, and if the rumours are true that Apple have been unhappy with Intel for a while now, and IIRC that Mac OS plays better with AMD than Nvidia anyway, I would not be totally surprised to see future MacBook Pros using AMD APUs, at least before Apple can figure out ARM.
The new Ryzen 3 outperforms Intel chips in almost every area. The question is how Ice Lake will perform. If I’ve Lake can match Zen 2 performance/watt, it would be more attractive to Apple because of integrated TB3 and avx-512.