Just spent a few days in Subic. One of the gossip items on the base is the construction of a substantial fueling facility on a US Navy contract. Apparently the deal is that the contractor will build and operate the facility, with the Navy guaranteeing a minimum purchase level over a seven year period.

Second hand news and potentially with inaccuracies, but the sources are reasonably reliable and if true it would suggest an intention to maintain a US Naval presence in the area.

I do not think it's likely that the Navy will be moving back into Subic in a major way. There's not a lot of space available. Since FedEx left the airport and most of the buildings around it are pretty much vacant, but the old NavMag area and most of the pier facilities are leased to private investors. With the fueling facility and the new shipyard (Korean owned but presumably available for repairs etc) there's certainly potential for a support role.