The source is the internet search engine, Google.
It's clear that the arrival of the Pixel 6 and the Pixel 6 Pro is a sign that the company is serious about the processor of the phone. The first-generation Tensor chip is a strong statement of intent for the company. There are rumors of a possible second-gen Tensor, with one development board being given the codename "Cloudripper". It seems that the name refers to running previously cloud-based computational tasks directly on the chip.
What about the A-series? The mid-rangers usually use mid-tier chips from Qualcomm. It can work within the limitations to ship phones with unique features like Live transcribe and Astrophotography. The recently launched Pixel 5a is based on the pretty unremarkable Snapdragon 765G. It's likely that the Tensor chips will eventually power the entire lineup.
It turns out that is happening. The upcoming Pixel 6a will use a chip from the company. The report can be confirmed by a source familiar with the device. The GS101 processor used in the 6a will be the same one used in the 6 Pro.