So regarding the selection criteria in fencing:
If a team qualifies for the Paris 2024 Olympic Games as per the guidelines of the FIE Olympic Qualification System, the three fencers who have earned the highest number of HPP ranking points (best 7 of 9 results by HPP ranking points, with a minimum of 4 senior world cups being counted) at FIE Senior World Cups, Senior World Championships, and Grand Prix competition between April 3, 2023 to April 30, 2024 will be selected to the Olympic Team.
So Gu was in the top 3?? Here is the rankings