I feel it is premature to say that Xe is going to kick Vega 8 to the curb without independent reviews. Given the shady history of Intel's benchmark, there is absolutely no reason to take their marketing results to conclude. It is highly likely that the tests were performed with significant advantage to their own setup.
While I agree to some extent that AMD should not have regressed from Vega 10/11 to a Vega 8 with Renoir, but it is also proven that the Vega 8 can still be faster than the Vega 10/11 due to the significant clockspeed difference. In addition, I feel the reason why they made the decision to drop from Vega 10 to 8 is likely due to insufficient die space to accommodate an 8 core processor and a bigger GPU. Otherwise I see no reason for them to cut back on the GPU. As to why not RDNA, I suspect it is a stop gap solution to make their GPU more competitive in the short run, but will ultimately be replaced by RDNA2. Which kind of made sense why the rumors mentioned that post Vega, AMD will be using RDNA2 for their APU.
I feel reception to the Tiger Lake announcement seems very poor. In my opinion, Tiger Lake is a significant improvement for Intel, but did not bring anything exciting along with it. Sure the Xe graphics are much faster than their previous UHD graphics, and potentially as fast or faster than AMD's Vega 8, but it is not groundbreaking fast. AMD's APU graphics was significantly faster than any of Intel's UHD graphics back then, to the extend of being 2 to 3x faster in some cases. This was shockingly good back then which stirred up excitement and interest. In this case, Xe may potentially be faster, but the gains is nothing to be excited about in today's context. In addition, any excitement for Tiger Lake probably got tossed out because Intel scheduled their announcement 1 day after Nvidia's Ampere announcement.
Then again on the CPU side of things you have the same 4 core design which is getting long in the tooth in 2020. One can argue that Intel is still supreme when it comes to single core performance, but Renoir packed the surprise of 6 and 8 cores (highly competitive cores) which was unheard of on the ultra low power class of processors. All these likely contributed to making Renoir such a hot topic along with hot demand. I am using an Ice Lake laptop, and to be honest, I can't care much about Tiger Lake. In fact I was thinking of selling it to try out the new 8 core Renoir which sounds more exciting to me.