If you read my post I said "should" not "will".
I got the info from Virgin Media themselves :-
Quote from their website :-
"Back in October we announced the launch of the new Hub 5 and we’ll be offering this to customers at no extra cost as part of a phased rollout."
Also from Virgin Medial website :-
"How to get a Hub upgrade
If you become a Gig1 Fibre Broadband customer customer, you have the option to upgrade your router to an even faster WiFi Hub, at no extra cost! Serving up average download speeds of over 1Gbps, it’s built to deliver incredible levels of speed and connectivity.
To request a Hub swap or upgrade, simply use the Virgin Media Connect app or sign in on the My Virgin Media app to find out if you’re eligible. You can also check eligibility using the link below."