FFLfag again,
I can now 100% confirm. NICS phone line is shut down. Called like I was going to do a background check and got the following message.
"The NICS phone system will be shut down for a short period due to technical difficulties. Please try your call again later."
E check appears to be functional though but I don't have a login to confirm that.
Also, if you're in a state where a handgun license exempts you from NICS background check, like Texas where I'm from, you can still legally purchase from FFLs. Big retail locations probably will not honor this but small mom and pop type stores or home dealer FFLs should be able to legally sell to you.
Face to face private transfers are also an option and some social media sites like MeWe have gun groups to get that done.
I'll update with new information of it becomes available.