What is the rationale behind requiring a meeting before filing academic misconduct charges?
I believe that the main impetus for a meeting with the student is to inform them directly that they are being charged with academic misconduct, and to know that they are consciously aware of such charges, so that they cannot claim "no one told me." In general, until recently, at my school, the process dragged on and on because the students need to sign a form indicating their willingness to accept or refuse the sanctions. 

However, in recent years, this process has become more digital, and, for instance, at my university, the school no longer requires a face-to-face meeting. The forms are filed and processed electronically, and notification of the intent to file charges can be provided to the student via the campus email system.