I currently have a Disney+ subscription managed by O2 from a previous deal I subscribed to. After muy free 6 months, I kept it on at £4.99 a month. I am now wanting to upgrade my phone. If I do that, I am being offered a similar deal, free 6 months Disney +, but it will now be £7.99 a month after that runs out. If I choose not to use that option on upgrding, will I lose my current subscription?
It makes no difference to your current subscription if you upgrade.
You will still carry on paying the same you do now if you do nothing to your subscription.
There's no need to take another free offer for 6 months if you wish to retain your current subscription charges.