The first Apple Silicon hardware of the year was the Mac Studio, not an upgraded MacBook Air or MacBook Pro 13. According to new rumours, Apple will release the next MacBook Air this summer but with diminished specifications. For some reason, this year's MacBook Air is now believed to feature the Apple M1, not the long-rumoured Apple M2.
https://www.notebookcheck.net/Next-generation-MacBook-Air-rumoured-to-launch-this-summer-with-a-new-design-but-no-Apple-M2-SoC.607311.0.html
I would think Apple would try and create separation between the base model lineup and the Pro line. Keeping the Macbook Air on an older chip while giving the Pro models the better upgrade chips creates that separation. I especially think this will happen because of the chip shortages. Apple would obviously rather secure chips for Pro models because margins are better than for a Macbook Air or Mac Mini.