Why is it taking so long for Verizon Wireless to release Windows Phone 8.1 for the Nokia Lumia Icon? Is there an intention by Verizon Wireless to negatively impact Nokia phones or Windows phones? They certainly support Apple iOS upgrades as rapidly as possible.
Placebo. Apple waits until all their devices are ready to update. They don't update a single device when they are ready with that one.
GSM devices should always be updated first. They don't have additional testing from Qualcomm like CDMA devices have.