Maybe this is different on cars newer than 2015 but I've never felt cruise control apply brakes.

At most, I've felt it shift down (on an automatic, obviously) to use engine braking while it was trying to reduce speed going downhill.

Any other time, it's only slowed down by coasting.

It lets off the accelerator to reduce speed to the new setting, just like a human would.

At least on the cars I had over the years, it does not apply the brakes. Depending on how far it is from the target, it lets of the trottle and it uses engine breaking.

Regen