So you only want it to trigger when it is the only column that has changed, and that column is checked, or equals yes, etc.

If the user unchecks it, the flow would run, it would evaluate as true for the "Has Column Changed", but because you also are checking against the column value, the condition would be false and it would not send the email.
If the user modifys that column again, it would trigger another email.
Hope this helps!