Not quite true. Verizon is planning to sunset 2G in 2019 [1], and is making efforts to get customers off 2G before that (similar to what AT&T has been doing). They are also rumored to be planning to shutter 3G in 2021. This leaves only T-mobile and Sprint in the US market providing longer-term 2G support, and their coverage is not great if you need to deploy devices outside major metro areas.

[1] https://www.wirelessweek.com/news/2016/07/verizon-targeting-...