31 May: FF15 Event with Ignis (41:42). Collectors event, where you can trade for items.
11 June: 30th anniv special dungeon with warrior of light wardrobe (42:09)
14 June: FF3 Challenge event w/ recruitable Barbariccia (42:32). Revenge event for ff4 on 17 June with Palom/Porom adult wardrobes
20 June: Dissidia Collab event (43:00).
24 June Summer Sun Festival 2018 (Fest event) (43:30):
New gift dungeons added for 14 days, can earn 52 mythril. Begins 24 June. Similar to the gift dungeons in 3rd anniv.
Special event where you will fight the weapons from FF7
New quiz dungeon with ragtime mouse. He will ask questions about scenes depicted in the record dungeons released from may 30. Can get new music records from ragtime.
25 June, Music record dungeon released, where you can search for music from the games. Duneons are low difficulty, and you can find music for your music hall.
Unparalled Darkness event where you fight Zeromus. One of the strongest bosses ever faced in ffrk.
Power up dungeons unlocked.
Relic draws and login bonuses:
Special relic draws to celebrate Overhaul and relic draw (48:40) (these look like the ones from the 3rd anniversary survey). Overhaul Relic draws in 2 phases, first on 30 May, 2nd on 1st June. No word if these will be full price, half price, or free. The video shows 2 banners (phase 1 and 2). Phase 1 banner shows cloud/noctis/rosa/ok and phase 2 shows Lightning/kain/relm and OK again. No indication what types of relics (ie USB/BSB/SSB on each banner). /u/guadosalam suggests that these draws are the same as JP: Here and here.
Realms on Parade start 9 June. Note: as in Japan, 15, T and type 0 still share the same banner. Everything stays the same as last parade, including price.
3 phase lucky relic draw for summer sun festival. Phase 1: Elemental infusion burst/ultra. Phase 2 is 5 star or higher overstrike (I assume these will all be 6 star). Phase 3 is a '5 star or higher' USB only lucky draw (do these guys even play their own game)? Edit: Translation here is pretty confusing, so you can read for yourself at around 50:10 of the video. /u/LilitthLu suggests phase 2 and 3 will be one guaranteed 6* with the rest of the pull being 6* or less
Summer sun festival will have new arcanes and chains. Lineup for these banners still under wraps.
Login bonuses:
From 24 June, there is a login bonuses including 10 mythril and other gifts for the summer sun fest.
10 mythril for everyone for watching this video (will be in inboxes on 25 May). (thanks to /u/clithertron)