Escort aka Payload modes see one Overwatch team tasked with delivering a "payload" to a certain point on the map and the opposing team tasked with stopping them. In this mode, it more about strategy than annihilating your enemies.
How players respond to the forthcoming Rialto map will remain to be seen, however, it's now live on the game's PTR (Public Test Realm) for PC players. Naturally, it will roll out for console players at a later date.
An official post from Blizzard on the Overwatch forums also revealed that damage from Tracer's pulse bomb would be reduced from 400 to 300 and that Brigitte's shield bash hit-area is reduced from 90 to 60. There are a few other changes as well, so if you're a major Overwatch gamer, definitely
peruse through the forum post.