Following up with a potential supervisor
Your potential supervisor, like pretty much everyone else, expects useful professional correspondence. By useful I mean that they expect to learn something new from it. If no event has taken place that would warrant a change of state, your potential supervisor has no reason to assume that your position has changed. Therefore, there is no need to send any email, that would confirm something they already know.

Two weeks is by no means a long time for an admission process status update, so, that needn't worry you. However, if the process would take a disproportionate amount of time (how much depends on local factors), I would consider emailing the professor again. But that is a change of the circumstances as explained above.

Another case in which I would consider contacting the person is a reminder. That is usually the case when you expect them something to do or if you got no response the first time. You state that you already communicated a change of state and that they acknowledged it by thanking you.

Bottom line, if you have nothing new to report, nothing to inquire and no need to remind the recipient of anything, there is no need to send an email.