Hello David
If you have set up an L3 Etherchannel like the one in the lesson, and during its operation, one of the physical links goes down, you should not lose connectivity. You should still be able to ping the other side. That’s one of the advantages of Etherchannel, it delivers both higher throughput, but also reliability.
At the moment when the link goes down, you may experience a momentary loss of connectivity, if that physical link was being used for communication at that moment. However, this should only be momentary, and within a couple of seconds, connectivity should be restored.
I hope this has been helpful!
Laz