Possibly? Yes. You've touted the word 'definitely'. I see no convincing argument supporting it would be a greater danger than an opportunity.
It's probable enough in my mind that it does hurt AMD for me to make my own decisions about my investments. I can't say for sure that it will damage AMD and I never said I thought their share price would tank (actually I stated I thought it still might hit $20) but the decision to give intel their gpus as a showcase for intel's EMIB instead of producing their own integrated solution with Ryzen tells me that, at the least, AMD doesn't think they can sell their own chips on the high end market even if they vastly outperform intel's solutions.
Would Intel be able to produce a CPU/GPU+HBM chip integrated with EMIB without AMD? Maybe, with nvidia's help they could... but clearly there is some issue with them working with nvidia on this at this point. What is to stop intel from dropping AMD and using nvidia GPUs next time?
Why didn't AMD integrate Raven Ridge or Pinnacle Ridge with HBM? That solution would perform nearly the same as intel but would use less power, and it would allow AMD to compete on the high end with vastly more powerful notebooks. The only answer I can think of is they don't believe they can sell their own products. That tells me that AMD is acting as a subordinate to intel instead of competitor.
This whole deal stinks of short-term gains being put above brand recognition and marketshare aspirations. When I invested in AMD, I thought they could improve their brand image to the point where they could compete with intel on an equal basis. I saw their share price going as high as $50 by 2019. This deal tells me that will never happen, because AMD would rather piddle around in budget markets and gain a bit a revenue here and there rather than compete head to head with the big boys. So I'm out.
I never told anybody else they should sell nor did I ever say this was guaranteed to lower the share price or destroy AMD. I do think it's definitely bad for AMD in the long run to hurt their mindshare in this manner, but I don't pretend to be infallible. I may be wrong.