T-mobile USA says they’ll shut down 2G in April 2024, leaving only 4G and 5G.
https://www.t-mobile.com/support/coverage/t-mobile-network-evolution
That means VoLTE will need to be fully, officially operational on the L5 BM818-A1 at least by then, Purism. 
Keep up the good work!
… depending on what the other networks in the US are doing? Or have they already closed 2G and 3G?
To quote the Resident Alien… “Well, that’s some bullshit!”
I have been very happy with T-Mobile 2G calls on the L5 – great clarity, seamless automatic switching between 4G data and 2G calls, so much so that I haven’t felt the need to turn 4G on. I guess that will change next year.
I will look on the bright side… 4G calls will mean simultaneous data and calls!
Some providers have better coverage in some areas than the others. It’s almost like they divy up territory amongst themselves.
The three major carriers are T-mobile, AT&T, and Verizon. T-mobile is the only one that still has a 2G network.
A fourth, smaller carrier, U.S. Cellular, is only available in certain regions; it’s currently shutting down 2G market-by-market, I believe. Incidentally, it’s the only carrier planning to retain CDMA, according to Wikipedia. (Previously, Verizon and Sprint used CDMA; Sprint merged with T-mobile in the last year, and CDMA was shut down.)
All the remaining providers are MVNOs of T-mobile, AT&T, or Verizon.
Unless we have a different North America modem by then, that is.
Some other shutdowns around the world:
So by that link (the second one), 3G is already gone in the US. However you can easily see that the date given for the demise of 2G is inconsistent with the date given in the link in the OP. So take with a grain of salt! It is hard work keeping accurate, up-to-date records about every carrier in every country in the world.
I think IoT will miss 2G/3G. The reality is that a lot of applications don’t need the multi-megabit bandwidth of 4G (much less 5G) and so there will be a lot of otherwise needless scrapping of equipment. Still, that’s progress and it is inevitable. I think, in the context of IoT, it is more likely to affect businesses than individuals.
One area that will affect individuals is back-to-base alarms. Back in the day, the alarm would always use the PSTN. However that is a security weakness. So for this and other reasons alarms started to use either 2G/3G for the telecommunications or at least use it for backup. A lot of that equipment would be fairly old by now - and it will need upgrading or scrapping.
T-mobile USA are apparently about to start their 2G shutdown: T-Mobile Network Evolution | T-Mobile Support
Capacity and coverage of T-Mobile’s 2G (GSM) network is expected to change starting as early as September 1, 2024.