ANY communication gap is a leadership gap.
Students don't always step into the classroom knowing how to communicate. The fact is, most of their digital lives happen in spaces where emojis replace nuance and "k" passes for a sentence.
Online courses often strip out the nonverbals that make face-to-face communication work. No body language. No facial expressions. No vocal tone.
I think the most important mindset an instructor can have is that it's not their job to police tone. It's to model what professional online communication looks like before problems emerge.