That is very debatable. VZW competes mostly with themselves. Much of what people claim is a response to TMo on various fronts is related to VZW wanting to get out of the subsidy business, something they expressed long before people thought TMo would still be operating.
And a lot of the other family share stuff is VZW responding to maximize revenues in a market where more people have devices, and multiple devices. VZW has offered very little in incentives and plans to single users with one device.
Big Red is and has been content to let TMo take the lower margin customers. They compete with TMo about as much as Mercedes competes with Chevy.
Didn't verizon launch a campaign to get their customers back who went to Tmobile? They are very much paying attention to them.
They also raised their Gigabytes per dollar in defense of Tmobile as well.
Tmo might only be the third largest now, but AT&T and Verizon can't rest on their laurels. Tmobile is getting stronger at their expense everyday.