That's weird, because it's directly contradicting that the carriers themselves say they have decommissioned it.

https://www.fcc.gov/consumers/guides/plan-ahead-phase-out-3g...

I don't believe there is a contradiction.

The FCC page you linked is talking about major carriers decommissioning 3G.

The grandparent comment is talking about rural/remote areas that no major carrier served in the first place.