Reportedly, Google will reserve some of its latest Pixel camera features for the Pixel 6 and Pixel 6 Pro, even after the Pixel 6a arrives. The Pixel 6a will feature at least of its sibling's cameras though, plus their Google Tensor GS101 chipset.
https://www.notebookcheck.net/Pixel-6a-Google-s-next-mid-range-smartphone-will-not-support-all-Pixel-6-and-Pixel-6-Pro-camera-features-even-with-the-same-Google-Tensor-SoC.614501.0.html