So several strategies for everyone to think about to "price protect" to hedge for expected ticket price/changes...
1) If you plan on DLR annual pass, purchase it late summer before Labor Day 2018 to cover opening date for Disneyland SW:GE summer 2019 opening (Signature or Signature Plus to not have blackout during opening day).
2) You can buy multi-day pass now and use it for the opening (Mult-day tickets must be used within 13 days of first use or by January 13, 2020, whichever comes first).
3) One-day tickets bought today are valid now through December 31, 2019. One-day Peak ticket can be used for any day (Peak, Regular or Value).