The word get is used in your examples in the sense of become.
First, to be confused with something is an unusual expression. We are more often confused by or about a matter/issue/intention or whatever. However, it's perfectly grammatical.
Leaving this aside, there is very little distinction between the senses of be and get in your examples. For most purposes, they are interchangeable.
However, get confused implies a process of becoming confused over a period of time, whether minutes, hours or weeks, possibly as a person becomes more involved in a subject or issue.
Be confused simply states that the matter in question is confusing to someone without suggesting the process of becoming confused.