I could see that.
IMO, this is how the next few years go:
2018 - F&F, Volcano Bay expansion
2019 - Potter thrill ride, T2 Replacement...Shrek replacement(?)
2020 - Shrek replacement, Nintendo, MoM(?)'
2021 - MoM, Something else for IoA
This gives the existing parks a good, solid base. It'd be the perfect time after 2021 to really work on Site B, while giving USF/IOA some small upgrades while that's being built.