Yes - unfortunately the API would automate creating the replies, but it wouldn’t really solve the clutter problem: for a topic calendar the individual calendar entries are still represented by individual replies.
I’ve just found an existing feature request which is almost exactly your use case:
Their example is a course occurring on twelve consecutive Wednesdays, and they make the same point: creating every occurrence individually is tedious and clutters the topic.
They suggest allowing recurrence in Insert date / time together with an end date for the final occurrence, which sounds very close to what you need.
So rather than building an API/Power Automate workaround that generates 52 posts, that feature request is probably the better place to add your school-calendar use case.