Not really. They still can do quite a bit of fingerprinting.

And many companies don't need a lot of fingerprints. To give an extreme example, if you sell snow blowers, all you need is location data to know if someone lives where a big storm just hit. If you see an IOS device, you know that person probably is more affluent. If Android apps are your business, that's not your target.

See

https://digiday.com/marketing/what-is-device-fingerprinting/

And

https://medium.com/fast-company/browsers-are-rushing-to-stop-shadowy-supercookies-that-spy-on-your-activity-d50f16eed436

As to Instagram and Facebook, of course Facebook can see Instagram use and vice-versa. Duh!