Why is this changing?
We’re increasing the amount of sport broadcast via Ultra HD in 2022 and beyond. This means there will be times where multiple events need to be broadcast via Ultra HD at the same time.
To cater for this, the single Fox Sports Ultra HD channel (Ch. 508) is being removed and additional broadcast space is being added to better support the extra content you’ll have access to.
While this change is occurring, from 21 February to 11 March 2022 you can continue to watch your sports on the Fox Sports HD channels.
When will Ultra HD sport become available again and how will I access it?
Depending on your box type, Ultra HD content will either be broadcast via Satellite or streamed via home internet. To access all available events in Ultra HD, your iQ4 or iQ5 box needs to be connected to the internet. You’ll also need to be subscribed to the Sports and HD packages, and have a compatible 4K TV.
Ultra HD Sport channel changes (closure of Ch. 508) - Foxtel website
To me, those 2 things suggest that it’d be accessed via satellite (for satellite users) but to access the channels you’ll need to use the menu system (and you need access to the internet for a lot of the menu features). This would be similar to how Sky in the UK do it.
If you were to replace a UHD channel with pure UHD streaming with all overhead of live streaming in UHD, I feel it would be easier and more pleasing to the customer to build a UHD on demand streaming movie library which can buffer than to try and move everyone watching sport in UHD over to live streaming.