I think Amazon mentioned they intend to use their own chip on All of AWS except their IaaS / EC2 offering, where you still get to choose Server running on x86.
That is why it was mentioned as the fall of x86 on Servers.
And AWS' initial strategy is to move its internal services to Graviton2-based infrastructure. Graviton2 required significant investment, but AWS can garner returns and improve its operating margins due to the ability to cut out middlemen involved with procuring processors, power savings due to Arm and efficiency gains from optimizing its own infrastructure.
AWS services like Amazon Elastic Load Balancing, Amazon ElastiCache, and Amazon Elastic Map Reduce have tested the AWS Graviton2 instances and plan to move them into production in 2020.
Normally I try to find Primary sources rather than secondary like Zdnet [1]. But I think those exact wording was quite widely reported at the time.
They say they are not Anti-Intel or AMD. Which is true. ( They are only Anti x86. ) And they say the same to UPS and Fedex at the time.
That is why it was mentioned as the fall of x86 on Servers.