Dropping anchor in a channel is something a container ship (especially one without other mitigations like this Newnew, I mean look at it) might do to increase stability and reduce the risk of drifting out of the channel.

I don't care to convince folks in this thread one way or another, but yes, there are reason a commercial ship would drop anchor while underway, including bad weather and a narrow / shallow channel. The circumstances from last year had both.