Ranking, belts, uniforms, certificates and the other trappings came from outside the FMA and were added on for various reasons, none of which aimed to improve the art.
And I think rankings, belts, uniforms, certificates, and the other trappings are silly. The Eskrima I have learned is carried in my body. It doesn't live in my belt, or a suit of clothes, or on a piece of paper. To know some Eskrima means to be able to use it, nothing more and nothing less.
Nor do I like the term system. To my ears this is just more silliness grafted onto Eskrima from the Japanese and Chinese traditions. It works perfectly there, but in Eskrima it makes no sense at all.
I like traditional Eskrima as described by Pedro Reyes in his essay The Fillipino Martial Tradition. He captures the spirit that makes Eskrima unique and effective. I don't like silly ideas that cut into the core of Eskrima.
My advice to you Shogun, is not to worry about rank, or your teacher leaving, or anything else. Just find someone who is good, and learn all you can from him. You are responsible for your own development. Don't get fooled by window dressing.