We were in WDW 9/19-9/26. In every online group I was in, everyone talked about "low crowds!!" but when we got there, it was not low crowds. Now, I haven't been in ten years, so it was objective to me, but my mom who goes at least once a year, said it was way busier than normal. Most rides were about 30 minutes and up. In DHS, ToT was 105 minute wait on 9/23. While it wasn't shoulder to shoulder, it seemed pretty busy. When we got back my mom read that the supposed 3 crowds were actually 8. So yeah.
Did it impact our trip much? No. Would I go again in September? No. It was SO hot and humid. I'd rather have cooler temps!