Hi Matt00 and welcome.
You can find here a small list of addons working on Orbiter 2016.
https://www.orbiter-forum.com/showthread.php?t=37446&highlight=orbiter+2016
Also if you were an user of Dansteph's DIGV, Ummu, UCGO, they haven't been updated yet for Orbiter 2016 but you can use the DGIV, it's working but might crash at moments.
Also Orbiter Sound 4.0 works on Orbiter 2016, while it isn't been updated yet.
Same for ISS A2Z, it's working, some modules have been updated for Orbiter 2016 but not all.
The main reason is the HUD, if your game crash when entering the cockpit, try disabling the HUD with CTRL+H before, via another ship first.
Also if you were a ShuttleFleet fan, it's over now but gattispilot is working to make it live again with Multistage2015 and it's awesome. As well there is also SpaceShuttleUltra for Orbiter 2010 and 2016.
And finally Altea Aerospace's ships are all up-to-date for Orbiter 2016. (Deltaglider XR-1, Ravenstar XR-2, Vanguard XR-5). They now use their own sound system known as XRSound. There's a bridge made by Face for Orbiter Sound and XRSound to work together.
The rest I'd say it's up to you to test them if they are working or not but in general they have an updated version for Orbiter 2016, especially MFD modules.
Happy orbits o7