I was planning to go last june to Tokyo with my family, but I saw that both Journey to the Center of the Earth and Space Mountain would be closed then. I changed my plans and went to Indonesia instead (and got a girlfriend there!)
I booked things for the end of September and it was perfect. Only ride closures then are Jungle Cruise, Swiss Family Treehouse and Jumpin' Jellyfish. Will be my parents first visit to Tokyo Disney and my girlfriend's first visit to a Disney park period.
Looking at the closure calendar that stretch until March 2019 right now, Indiana Jones is closing in January as well as Aquatopia. The Little Mermaid show is a March closure. Over at Tokyo
Disneyland, Roger Rabbit will have a long two months closure, Splash Mountain is down in February as well as Star Tours. So all those rides will be ok for May and June 2019... Check back in September when April refurbs are posted and it will help you get a clearer picture.
My deal breakers are:
- Indiana Jones Adventure
- Journey to the Center of the Earth
- Tower of Terror
- Sindbad
- Space Mountain
- Pooh's Hunny Hunt
- Monsters Inc. Ride and Go Seek!
If any of those rides are closed when I plan to go, I will strongly reconsider my trip... if two are closed, I go elsewhere.