Can you, with respect to the rules, not feasibility, damage a defense during auto?
Feasibly? Yes, but it would take two robots, and one of them to have an auto that can turn and follow a robot through a defense.
Unless the two robots in question can only cross that one defense, what is the benefit? Damaging one defense scores the same as single crossings of two defenses, whether in auto or teleop.
If your auto routine is able to cross three categories of defense (in our case, low bar, B or D), you should always be able to have your own defense to cross for auto.
I see at least two benefits to being able to cross a defense after another robot.
Low bar will likely be the most consistent location for auto routines. This is both because it will be in a consistent location, as well as the fact that the low bar is probably the least likely to cause alignment issues while trying to cross it. I have a feeling many teams would be more consistent scoring with 2 low bar routines (for being 1st bot and 2nd bot through the low bar), than trying to score a boulder after crossing the rock wall or rough terrain.
Having a second bot run through a defense could set you up to run a 2-ball assist auto with a high shooter and an assister.