This really is every org, even if someone starts lukewarm to an idea it can percolate, get established and then come back out again as a fresh opinion without any malice intended. It’s always fun to get your own ideas back almost verbatim.
From this example the same feeling would be generated by someone else internally already working on the same idea without needing any prompting from anyone in the actual meeting. This can actually be quite common in games where people will give a lot of unsolicited design ideas as feedback or part of bug reports. There's going to be collisions there without anyone's ideas being copied or stolen without credit.