We already have FIVE shirts a season ... the three that we see on the pitch, a fourth that is the eSports one which that team wears while they play video games (yes, that actually happens and yes we have an official eposrts team where we actually buy these players and pay them too) and then the fifth that comes out now annually for the Chinese New Year. However only THREE remain the main ones that are used by the (men's) first team on the pitch, which will change to FOUR now ... (actually women's team has already wore a fourth on the pitch - the Chinese New Year one this season).
What I heard (before today's leak) is City wanting to become the first team in England to come out with two home shirts and two away shirts (one set for the league and one set for the cups -or- a Domestic / Europe divide or something). United and Liverpool have also floated the idea previously as well, and I think we're trying to get ahead of them two and be the "trendsetter" ... when third kit came out, it was for supposed colour clash situations (but we were the first ones to start calling the the cup-away shirt to differentiate from the league-away), now welcome a cup home in addition to the league home short as well ... two sets of sky blue home shirts to buy now along with the away and third (or will that be called fourth now )