Embarkation is unlocked at Sailing now so you get it a lot earlier than in 5.
Monty's Agenda is that he hates people who have Luxuries he doesn't.
Pangaea Maps are considered to have multiple Continents in terms of game mechanics.
Camps are unlocked at Animal Husbandry. No separate tech for Trapping.
There's new Strategic Resources in the game.
Toronto, Brussels, Lisbon and Preslav are new City States.
Toronto and Brussels are Industrial City States, a kind we haven't seen before. Toronto increases the range for bonuses from Industrial Zones and Entertainment Complexes by three tiles. Brussels gives +15% to Wonder production.
Lisbon is Trading City State and Preslav is presumably Military, based on it's red colour.
Shock/Drill Promotions are gone and replaced with a new Promotion tree.
Crater Lake gives +4 Faith, +1 Science. Counts as a source of Fresh Water. Holy Sites get adjacency bonuses from Natural Wonders.