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They do now but didn't originally. I bought a service vehicle (X) in Dec 2017 that didn't have it but they added it as part of the sale. Told me at the time that all the X were coming with it then.
Our 2017 Model X was stuck in downloading status for 2020.4.1 about 3 weeks, but it disappeared this morning.
I guess we'll need to wait for the next update now.