UK.Gov in incompetence shocker...
Regulate / interfere if it becomes abusive in it's dominance, not before it's even started. It's clear that sky/virgin can't distinguish between their sitting bone and their arm joint.
A product can't dominate a market that doesn't exist yet, and can't do anything other than dominate a market which it creates (at least initially).
Also - there is nothing inherently wrong with a dominant product in a market. The likely outcome is genericide (see sellotape, hoover, xerox) as and when other people enter the market.