This can be observed in the latest Projucer (on Big Sur), for example with the Module or Exporter checkboxes. The names and roles of the buttons are read out by VoiceOver, however nothing is read out regarding their state, regardless of whether they are selected or not.
If I understand correctly, this commit was made to fix an issue on Monterey, where VoiceOver would confusingly (to non-programmers ) read the states as “1” and “0”. On Monterey, things are working as expected and the states are being announced as “On” and “Off”, however I think this fix has potentially introduced a bug on Big Sur.
It seems like VoiceOver on Big Sur interprets 1 and 0 as “selected” and not selected, and for anything else (e.g. “On” and “Off"), it doesn’t read anything out?