Dan, I tried resetting the microphone using the command you listed but it did not resolve the problem nor did a prompt a dialog box when I opened Pd. 
> On Nov 1, 2020, at 10:26 AM, pd-list-request(a)lists.iem.at wrote:
> 
>> You can also reset Microphone permissions system-wide, then (re)start Pd. In Terminal run:
>> 
>>    tccutil reset Microphone
>> 
>> That should trigger the dialog, although it will also reappear for other programs as well.