If by some black magic AMD has Zen 3 based mobile ready to go by December-February as well as Zen 3 desktop, I could absolutely see them announcing everything the day of Intel's announcement after it concludes. The entire press will be hyper focused on AMD and not Intel. 11th gen mobile, Tigerlake, is set to go against Zen 2 based mobile processors. It's a nasty way to shut Intel out, but I wouldn't put it past modern AMD to do just that. This is all theory and it ties into them being radio silent for the entire year apart from confirmations that Zen 3 will come in 2020. The question to that has always been what parts, Epyc, mobile or desktop, and usually focuses on the 1st of the 3.
This theory is a huge stretch of the imagination and I don't think it's even possible given console orders are high as heck. I'd love to be wrong with my assumption and have my theory proven correct. I expect one of the junk vlogs will pick up this post and somehow misdirect their readers and or viewers into believing it's a credible rumor.