"Total Eclipsa the Moon" will be Eclipsa's trial.
Something related to Eclipsa or Meteora is going to hit the fan, leading into "Butterfly Trap." Either Meteora will crash the trial, or Eclipsa will be unfairly found guilty and Star will allow her to escape. "Is Another Mystery" will be a Buff Frog episode where he discovers some clue to Eclipsa/Meteora's plan.
Something will force Marco and possibly Star to leave Mewni and return to Earth, as evidenced by the sequence of episodes "Marco Jr." (episode is confirmed to feature Angie,) "Skooled!", and "Booth Buddies" (possible return of Gustav/Charlie).
Tough Love is most likely a Meteora/Eclipsa episode (if Meteora crashed the trial), though it could be a Star/Moon episode (if Star allowed Eclipsa to escape.) It will NOT be a shipping episode.
April 7th will be a 20 minute episode attempting to deal with Meteora and Eclipsa, but whatever happens will fail and Meteora/Eclipsa will take over Mewni or be in a position to.