Yeah, sort of like moving through the Rialto map or King’s Row. But instead of just being essentially an escort map, they could spice it up by forcing the team to split up.
2 separate control points must be held simultaneously, “scavenger hunt” for items while swarms of omnics and omnic specials come for you, being taken down means that you have to pick a new hero, etc.
Left 4 Dead showed us that there is a huge appetite for Co-op survival modes, and I think if they had the time and resources to flesh it out, Overwatch could actually pull it off. It’d definitely help keep things fresh and retain players.