Aizen needs Ichigo fully matured; Gin knows the reason for this; Aizen thinks Gin is capable of killing Ichigo to thwart the plan.
Sounds like a plot, finally. Just no explanations as ever of how captains fall without using bankais, of Hueco Mundo-stranded characters, etc.
Next chapter probably Isshin and Ichigo chatting on their way; it turns out what Aizen wants is different from what they imagined.

