It was a test for more to come...
Personally, I had an “SOS” on my phone where the signal strength would be. There is a mode where you can use WIFI to make outgoing calls, but couldn’t get that to work. I suppose this WIFI call mode is mainly for 911 calls.
If you have a router at home with a WiFi provider such as Verizon, you should have no problem in making calls because the calls are going over the internet.
You aren’t using cell towers.
All of my calls are wifi calls as well as everything else on the internet.
Zero costs on my phone for anything other than my monthly wifi bill.
I only use cell service when I am not at home.
Same for me and how many other tens of thousands or millions of others?