PCM1864: Proper connection of electret microphone and Audio ADC

I'm trying to make a linear microphone array, similar to the TIDA-01479 Reference Design. I'm also using the PCM1864 Audio ADC, but using electret mics, instead of the MEMS used in the reference design. However, I can't find explicit information on how to connect an electret mic to the ADC. The Reference Design seems to connect each (MEMS) mic in differential mode, using VIN1M and VIN1P for example, through DC blocking capacitors, one on each terminal of the mic, being one of those ground. However, the datasheet for that mic has an example connected as single-ended only, as do all basic electret mic circuits I could find so far.  Checking different Audio ADCs, the PCM3052A datahseet shows the application using a differential connection for an electret mic, while TLV320ADC3001 datasheet shows a single-ended connection, but no explanation about the choice of connection.

Are both ways (differential and single-ended) valid for electret mics or does it depend on the ADC I am using? Where can I find more information? In the case of single-ended, that seems to leave me with 8 analog pins for the mics, but I'm only using 4. Should the remaining pins be connected to ground or another pin?

Thanks for the help