Very seriously doubt this one is true, as both Clark and Subic Bay are former U.S. military bases (which the U.S. military left in 1991).
That being said, Subic Bay had been used as an Asian hub for FedEx in recent years, while the former Clark Air Base is currently undergoing a major expansion to eventually become the primary international point of entry into the Philippines (and eventually replacing Ninoy Aquino International Airport in Manila).
Given the way these two facilities are currently set-up -- and the fact that it takes at least 10 years from concept to reality for any Disney attraction/theme park to open, I would file this in the "rumor" category.
Besides, it would appear Disney is betting its' Asian future on current parks already operating in Tokyo/Hong Kong/Shanghai...