I don't see any replacement props for the Mavic Pro in the DJI store. Are the newer "low noise" props compatible with the original MP?

They are. They are quieter and give you a bit more flying time. They are a bit thinner than the originals.

Yes, they work fine. I'm on my 4th set.

The low noise props designed for the platinum model work perfectly with the original MP but not sure if the low noise props designed for the Mavic 2 series are compatible.

Yes, I just purchased a set

Hello and good day Ray_Dunakin. Thank you for reaching out and for the inquiry. I would recommend to check the DJI Mavic Pro Low-Noise Quick-Release Propellers for your DJI Mavic Pro drone. In addition I would recommend you to purchase the said propellers from our official online store for you to be able to be sure to get genuine DJI merchandises for reliability purposes. For your reference I will be posting a link where in you can find the official DJI online stores. Thank you.

https://www.dji.com/where-to-buy