Found this Previous AMD Forum thread similar to what you are asking. The User is also a Youtuber like yourself: How do I get Sponsored by AMD ,Who Should I ask ?
Here is another previous AMD Forum Thread concerning AMD Sponsorship: Are there sponsorship possibilities?
From AMD Reddit: https://www.reddit.com/r/Amd/comments/7v02px/amd_sponsorship/
I've talked with Robert two days ago, he said AMD doesn't sponsor people upon request for any reason. They will reach out to you if they feel like you're deemable worthy.
Pretty much yep.