Wondering if anyone knows the answer to this. UA is offering 20% discount for indicating checked bags during OLCI. Is UA having this information (pending checked bags) in advance, rather than at the airport, information that helps them in operations planning - as it relates to weight issues?

As an extreme example, if everyone on a particular flight did OLCI and indicated how many (if any) bags they are planning to check, is this (in)significant enough that the airline could opt to order extra/less fuel for the flight, and/or limit the amount of additional last minute tickets it sells?