When there are empires no longer existing, the game doesnt take that into account when it comes to conditions that refer to "all empires"
This is why there is a civic that can never be unlocked, when one empire has fallen and the dictrine effect giving a techto all empires if at least 50% of the empires got that tech will never trigger if there are only 5/10 empires left. these are the 2 that i found, not sure if there are more.

One could say it is a choice of game design that this always refers to starting numbers, but imho canceling out some effects because the condition doesnt work with the current number sounds wrong. This is why i consider this a bug, not a discussable design choice.