Converted because this isn't a response from PM, which I think is what the asker wants. It does explain why the problem happens, but, again, I think the point of this was not to ask why, but more ask if it can be changed.
On a related note, an option to switch between different generations on the pages for moves would be very useful. If a Pokemon can learn a move in one generation, but not anything, it can get a bit confusing because the site only shows info on moves for the most recent generation, at least, on the move page.