Here's what the official site says:
" Join over 1,000,000 people and use Netflix Party to link up with friends and host long distance movie nights and TV watch parties today! "
So, yeah. Have fun.
I’ve actually been working on modifying their extension to make it better. I’ve gotten a code dump herehere of the latest version of their extension.
Because I’ve been looking at all the network communication the app does, I have seen all the data the extension sends to the server. I can safely say they are not sending any personal data or collecting anything nefarious from your system.
Here’s their privacy policy as well: https://www.netflixparty.com/privacy