I would define meaning as something larger than myself that gives my life direction and purpose. Without that, the Stoic's quest for Virtue feels like self-agrandizement, a ego-driven exercise that is ultimately meaningless when we are faced with our own extinction. Hence, what you hint in your article is true: without Logos the whole edifice of Stoicism comes crumbling down because there is no rational justification to be virtuous.
That something larger than oneself could the good of Humanity, which is the meaning found in Progressive and Marxist philosophies. However, on a closer look this is unsatisfying as a compass for ethics. For example, it cannot explain why the extinction of one species is morally wrong.
I do not believe in God, but I think that when we look at the Universe as science has shown it, we see a progression towards complexity that ends in consciousness and the ability that we have to understand the world. This past progression hints of a future progression in the same direction. If this is true, then our individual lives and the whole of Humanity could be seen as part of this larger progression towards knowledge, which gives the Universe a meaning. Maybe this idea could rescue the Stoic's concept of Logos in agreement with science?