UPDATE September 7
Phased rollout of native Apple Silicon support has begun to Macs with M1 / M2 processors. Barring any unforeseen issues, rollout will be complete by September 12 / 13 depending on your local time zone. See this thread for details and FAQ.
Seeing the graphics improvement from the native Apple silicon support is predicated on you using the latest Zwift Launcher app to kick off your session. As noted previously, Launcher v1.1.10 also gives you the ability to defer automatic game updates. Download the latest launcher + game version here.