Short answer seems to be "no". Long answer: Even if the Intel Iris "GPU" could handle it, your MacBook's resolution is "only" (you crazy kids and your resolutions...) 2k, you wouldn't be able to see a difference.
I'm pretty sure 8K would lag on a Mac Pro let alone a Macbook Pro, unless it is an extremely well optimized video. In other words, it depends on the YouTube video - but on an integrated chip, it probably won't be too great.
Because whether or not the CPU will be fast enough (it probably is, but anyway...), your display is nowhere near high resolution enough (it will look no different to 4k), and the GPU does not support 8k resolution - and neither does currently shipping HDMI, Displayport, DVI, etc. i.e., even if your CPU can decode it, and your GPU can output it, no cable is available to attach to your Mac to output it to a display.
There's zero point trying to run it on a 13" display anyway - 4k is already well beyond what your eye can see on 13" anyway. 8K is only really useful if you're dealing with home cinema size displays or larger.