From what I have read, this will not be anytime soon. I think it ultimately depends on what happens with the Neo order, if they obtain all 16, as then all of the 330-300s are supposed to go. I believe most 787 are leased and so Virgin might not keep them. The 787 fleet are relatively quite young, albeit “old fashioned” layout. I think it will be 2026 onward before they would even start to retrofit (all neos to be delivered by end of 2026, all 330-300s gone)… do not think they will start retrofit until then. May be wrong, bur I think they have delayed a couple of new routes until 2025 because they need all the planes they have at the moment