No more 4k HDR DolbyVision DolbyAtmos on MAX (hbo) App

I have subscribed to HBO through Xfinity for several years, and have always used EXTERNAL devices (not xfinity equipment) to log in and stream HBO content. I was getting 4k HDR DolbyVision DolbyAtmos until HBO became "MAX", and they enacted three tiers of service:

• With Ads - $9.99/month
• Ad-Free - $15.99/month

With Max, we're introducing a new Ultimate Ad-Free plan.

• Ultimate Ad-Free - $19.99/month
  Stream select titles in 4K UHD on 4 devices at once, up to 100 offline downloads*

Subscribe through a provider? If you subscribe through a TV, mobile, or wireless provider, your provider will let you know of any price or plan changes.

I got no such notification from xfinity.... Suddenly without notice, everyone who gets hbo through xfinity are NOT getting 4k HDR DolbyVision DolbyAtmos due to this... This is not right, especially because I just started a new one year contract with xfinity! I should at least get the Ultimate Ad-Free version for the remainder of my contract, right??