Apple says the new HomePod mini 2 can be used as the default speaker on all Mac models with Wi‑Fi 6E or later. A single HomePod mini 2 may be set as the Mac’s default audio output, or two can be paired for stereo sound.
HomePod mini 2 compatibility
The previous-generation HomePod mini can still play audio from a Mac via AirPlay, but it cannot be set as the system default audio output. Apple also notes that using AirPlay can introduce audio latency.

