Will Cesc leaving cause domino effect?

i hope we don't seen a repeat of 2007 when alot of arsenal players left, because for me i think the problem lies in there central defenders, i feel cesc is holding things together for the time being, but if he was to leave he'd probably start a trend with a few other players. the scary thing is that these players at this moment in time are irreplaceable, arsenal have one of the best midfield's in the world, and i doubt they could replace cesc and nasri especially on wenger's tight transfer list.