I think there is a good chance she has already redeemed herself by getting her team into prime position, but she and Brent may in fact win AR16.
Unless they backdoored their way into every following leg (save for the ones that they could afford to come in last in). But if they win it, regardless, it's going to be very difficult, if not impossible for someone to break the record of youngest winner ever.
Anyway, as mentioned, it will be interesting to see the casting moving forward. I think something similar also happened on Survivor. In S15, they casted someone that wasn't even 20 years old. Maybe they did decrease the age limit to 18 or something. Either way, it's not a big deal. I think Caite will be great TV, and as mentioned, she could be a completely different person and actually be a threat toward the rest of the field.
On a related note, it's pretty funny how they don't want to do another all-star season, but then efforts are made to get someone known.
The big question I would have is what would happen if something completely random comes up and it's a 21+ thing? I'd imagine that it wouldn't be an issue, but you never know.