Currently there is no plans for VM to use the O2 signal as at the moment the merger has not been approved, as far as I am aware the signal will still be changing to Vodaphone as the contract has already been signed.
The SIMs that are currently used and in the future are not rebranded SIM's the SIM's are Virginmedia own SIM supplied by a company in Belgium, it is only the signal of EE they use, changing to these will make the switch to another network seamless as no new SIM will be needed.
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks