I don’t think the schools would read into the timing of a tour. Particularly if a student is touring from out of the area. Plenty of kids are admitted to boarding schools without ever visiting at all.
Regardless of that, OP, we had a similar feeling after visiting what had been one of my daughter’s top choices. The tour guide was not great and kept making negative comments about a rival school during the tour. Honestly, that made it seem like he felt like he wished he were at the other school and was jealous of them.
He told us what a grind it was, that kids didn’t have much downtime or free time, etc. Just not the vibe my daughter is looking for at all.
Perhaps she would have felt differently with a different tour guide, but the school was immediately dismissed in favor of the many other schools she did enjoy touring.
Agree with the poster above - go with your gut. It can be really hard to let go of a dream or a particular program, but you need to consider your student’s happiness outside the classroom. The school will be their family for most of the year. Is it the family you would choose for them?