"People claiming that there will be a "true" "digital only" tv
antenna is ludicrous. Present day tv antennas will pick up tv signals
for the next 100 years. "

100 years? LOL

No one on this thread ever claimed that there was a "digital only"
antenna. However, most of the digital transmitters are on the UHF
band, so if one has an old VHF only antenna, they won't have to wait
100 years, they already are unable to receive most digital now.
Another issue is the location of the digital transmitters, which may
not be in the same location in every case as the analog transmitters
they are replacing, which means the antenna may need to be oriented in
a different direction.

And if you don't believe analog TV is scheduled to be turned off, just
go to the FCC website.