Yes, that's what I was thinking; that makes sense. Now what that top of wall to seal contact is supposed to look like and measure, I do not know. I also do not know what the top seal gap measurement is supposed to be in relationship to the bottom seal gap.
I do know that I got the bottom adjusted to seal tight but not so much that it stresses and tugs on the wall, like it was. It took me and my faithful surgical nurse (aka DW) about an hour to dial it in. For the "out" operation which was extending too far, our adjustment on the shaft nuts was about an inch. For the "in" operation which was tugging the wall on closure, we discovered that the stop can was out about a 1/2" too far; that's why it tugged too hard when we closed the slide. No more wall movement or creaking now!
When we first bought the coach and brought it home, I did call the dealer and explained this problem to the service manager. At that time, the shaft set nut was loose. He told me to tighten the set nut against the bracket and leave the nylock nut alone. He said leave it as the factory set it. That is exactly what I did. He told me it would "break in" without harm. I thought that was a wired, but I had never owned a unit with a mechanized slide. I wish I would have followed my better judgement from knowledge and experience and fixed it back then. Oh well, we got to it before any major damage was done. And we did it without beating the crud out of anything, doing stuff half-baked, or losing our camper for who knows how long to a dealer, where it would sit neglected and/or be haphazardly drug around and poorly handled.