Unity premium support was never included in Unity Pro. Are you thinking of something else?
then it was my own wrong impression.
To build on and hope clarify this, Pro Users have been able to purchase a Success Plan for access to Technical Support. Enterprise has access to Technical Support included.
No new changes here, nothing being taken away that was included before. 
You guys should really start looking into adding an own payment solution into the unity services.
Like google play, apple appstore etc. have, where they take 15-30% of each in app purchase sale.
There are a lot of markets opening up wit XR ( vr and ar) where there is no payment solution and they are not going through such stores ( in our case healthcare vr app). We would love to see an out of the box solution to sell inapp content while benefiting the company unity, our app does not go through any store and there is no inapp purchase solution we can use thrid party like xsolls etc. This could be such a revenue opportunity for unity.