Yes.. exactly.. you can't issue a 15y TLS (not SSL) cert today.. not in a usable way. If cloudflare stops proxying you, your cert is worth nothing (accepted by no one).
You can create your own without the use of cloudflare.. you can set it to a 100y expiry if you feel like it.
You can create your own without the use of cloudflare.. you can set it to a 100y expiry if you feel like it.