To me, as a forensics person, it's absolutely the case that there were other footprints. It's not going to be a big issue at the trial in any case. I've explained several times, so I won't again, but you can't have a latent footprint made of bio proteins without another footprint somewhere that isn't latent. If we posit that the murderer got only the tiniest amount of blood on his shoe, then there would be several more latent prints. If we posit that he got "some blood" on his shoe, then they picked those up with luminol.
I also believe he touched the slider on either the way in or out or both. But none of this really matters that much in the long run. It's simply not going to be hard to convince a jury that the murderer walked around the house. I can't imagine spending much time on such an obvious thing. I doubt they'll ever find the actual Van's, but I bet many donuts that they have 1) witnesses who remember seeing him wear Van's (curiously, in my own lab classes, if I ask teammates to describe what their teammates were wearing at the last class - without telling them in advance I'm going to ask - the top thing remembered is...shoes; for women, it's shoes and nail polish, if any) or 2) receipts for Van's. Of course the print will reveal one more little detail about the killer: his shoe size. The latent print, by itself, will also reveal a little about height of arch and toe length (a whole subspecialty in forensic anatomy).
If Kohberger has the same shoe size, same toe lengths and same arch height as the killer, that's just another piece to throw on the pile. If someone can testify to seeing him wear Van's, even better. If there's a receipt for him buying Van's, that's a trifecta on that piece of it.