I'm not sure if I read the developer update and did not understand but my clan and I have been "♥♥♥♥♥ed" many times in war by people waiting until after the war has been declared to start a defense. The defense, despite not being completed yet, shows up on their war base and then after the preparation day is over and war has started they cancel that building and repeat for every war they're in. This gives them the unfair advantage of having been weighted as a th9 during the matchmaking but now has th10 defenses during the war! For example, my clan was as matched up against a th10 who only had townhall 9 defenses which is perfectly fine. However, during prep day he built two inferno towers and now that war has started cancelled them but they still show up on his base and we are expected to attack that. I hope that supercell will consider that buildings shouldn't show up on your war base until they've been fully completed NOT in progress!