There shouldn't have been silence last time either but there was. There's nothing wrong with what city typically do, they provide the fans with every opportunity to get the atmosphere going. why would you want them to stop that in favour of some vision of an atmosphere we've failed to produce in the past when given the chance to.
If City play hey jude or bluemoon over the PA as usual, the crowd will sing it and there's your guaranteed great atmosphere for kick off. It's proven, it's good and it works, no reason to do anything different. There's 90 minutes without the PA system to follow it for the fans to sing without being lead.