Most people type the address into google. If the server says that the thing on port 80 is better served from port 443, then it can issue a 302 permanently move

Most people type the address into google. If the server says that the thing on port 80 is better served from port 443, then it can issue a 302 permanently move (and a HSTS header to make it stick). If the server offers different content on port 80 and port 443 then the server can do so just fine. The browser should not try to second guess my explicit instructions.