[Update] Verizon released an official statement which you can read below pointing out that the 2G and 3G networks will be available as long customers need them.
Verizon Wireless is giving several years notice that its 2G and 3G CDMA network will be phased out around 2021, though it did point out that these are guidelines. As more and more people move onto the new 4G LTE networks we’ll see more of the old 2G and 3G networks disappearing.
The new LTE network that Verizon is expanding is set to offer the same coverage as the old CDMA network by the end of 2013. Verizon is also making moves to introduce VoLTE which means that voice calls will run on the LTE network (currently just used for mobile data) instead of the CDMA network. This should also lead to a substantial improvement in the quality of calls for Verizon customers.
This is standard practice for carriers as they ramp up support for the latest versions of their networks. AT&T is planning to phase out its 2G GSM network by 2017 and Sprint is turning off iDEN next year. Canadian carrier, Rogers, is looking to support 2G until 2018. T-Mobile stands apart from the crowd with a commitment to maintaining its 2G network indefinitely, although that could change.
The vast majority of customers are on two-year contracts so they’ll get plenty of upgrade opportunities and should be shifted onto the 4G LTE network well before the deadline. The real concern is in the M2M or machine-to-machine space where it’s common to use the same equipment for longer.
According to FierceWireless Verizon's vice president of global strategy for M2M, Aparna Khurjekar, said “We are giving a decade worth of pre-warning” but she also promised “several years” of leeway for M2M customers that need it.
The Verizon Wireless 2G and 3G networks will be available into the foreseeable future. Recently published dates are guidelines that we are giving customers who have to plan, fund, and transition large enterprise projects to the faster speed networks. The Verizon Wireless 2G and 3G networks will be available as long as necessary to support customers who may have mission critical projects on those networks.