Yesterday, 08-Nov-2018, around 17h00 GMT our team of 30 players, all eligible for war was matched against a team of 28 players, thus putting 2 of our players in observer mode.
This is definitely not the previous behavior of matchmaking and what I'm expecting: a team of n*5 players was always matched with a team of the same number of players.
Only if your team members was not a multiple of 5 you risked that some of your lower level player had to take a break from war.
This is annoying, because our lower level members need the war coins and rewards to most!
Note that temporary removal of team members does not help either (and was not necessary in our case!): how could one be sure, that a team of 25 members will be matched with a team of 25 members?
Did somebody make similar observations when matchmaking for war?