Yes. Armed protestors storming the capitol and taking over the legislative chambers at the request of the defeated president is 100% a literal coup.
Breaching into government buildings in response to spurious allegations of electoral fraud is bad enough - there's no need to taint the message with embellishment, and doing so gives ammunition to people who want to claim that critics of these events are spreading falsehoods.
1. https://www.nytimes.com/live/2021/01/06/us/electoral-vote
Then again, the lack of firearms is probably why Capitol Police are playing it so calm.