Why not remove from the list or at least set them to the bottom in a non-player section for the current Event, as the rules always state late-comers to the Guild (after the event start) aren’t involved with the result? It seems confusing to have them on the active Event member list with their input to the result... as you say it won’t be used... or do you mean, they just don’t get the rewards but their points are adding to the Guild? Either way, tag them differently, so people know they’re not getting rewards, so they may not be so active this time round?
The rumble scoreboard doesn’t show people that joined the guild late, so I don’t know why events would be any different. Probably just another oversight that we’ll have to look at forever. So just keep spending on the game in about 10 years it will all be fixed I’m sure.
One of our alliance members was accidentally kicked out of a guild due to this -- they thought he was active but did not contribute to the event, when in fact he was a late comer.