Elon Musk was asked a question during Tesla's Battery day on September 22nd 2020 about whether Tesla would open up their platform to other creative people. Elon said that they will be providing Tidal music in all Teslas.
"We will be providing Tidal on Teslas. We're providing more music choices that people can choose from and generally just trying to improve the entertainment experience in the cars."
He went on to talk about how entertainment beyond music will become more important as Teslas come closer to autonomous driving.
This clip of Battery Day shows Elon answering the question at the 1 hour, 52 minute mark.
Update: Tesla has now released TIDAL music support in update 2021.40.
