New rules for yellow cards mean they only apply in the competition they are picked up in. Bissouma got his second yellow in this seasons fa cup which is a ban, however I believe yellows are wiped at the QF stage so he should be avaliable.
Edit it may be after the QF that yellows are wiped so he could still be banned. Means that it's impossible for a player to miss the final through yellow cards.
Can’t find anything relating to them being wiped at QF stage, but does state details will be released separately.....
http://www.thefa.com/football-rules-governance/discipline/player-essentials