Control's first DLC, Foundation, was released last week. I picked it up and have been slowly working my way through it. I'm not very far in, though.
It looks like the difficulty has picked up a bit. Or possibly it's just that there is a new type of enemy, and I haven't figured out how to handle them well yet. Control was mostly a ranged game, but the new enemies are melee who rush you with pickaxes. If you try to pick them off from heights, they start throwing dynamite at you.
Control also continues its pattern of having the main story line be reasonably hard, but having the side mission bosses be a difficult challenge. It's a pretty good pattern, because you never get stuck entirely. Since the side missions are independent, you can go after them in any order. Or skill up through the main story line first.
The story appears to be filling out some of the history behind the Federal Bureau of Control, investigating the time period before the main cast of Control.
In any case, Control was an excellent game, and Foundation is a worthy continuation.