This is pretty dumb that this bug is still with us. I’ve been reporting this bug here and to in-game support for almost a year now. Here’s how this glitch works:
1. someone in your clan is on the master CWL roster
2. they are indicating “I’m Out” for in-game war preference setting
3. that person either leaves the clan or is kicked
4. that person is still on the CWL roster, but now shows up as “I’m In” for war even though they are no longer even in the clan. There is no other indication on the CWL Change Members screen that the person is no longer in the clan.
What makes this bad is that it sets the clan up for accidentally including that kicked person on a daily CWL roster unless you exit the CWL screen and manually check to see if each and every person is still in the clan.
I’ve reported this to in-game support multiple times, they keep telling me they were aware of the bug and would fix it in the next update – that was 6 months ago.