What is the first Unity version with newtonsoft-json 3.0 enabled by default?

Hello,

I am creating a Unity package with newtonsoft-json 3.0 requirement.

JilleJR's page says newtonsoft-json 3.0 will be included by default in Unity now or in the near future.

Three questions:

What is the first Unity version newtonsoft-json 3.0 is included in by default?

What is the first Unity version newtonsoft-json 3.0 is included in by default and not hidden?

What is the status for 2021.2.15f1?

There may be some older releases my package needs to support hence the first two questions.

Thank you.