Are people starting a new Athiest movement without really understanding where their thoughts might lead them to?
More like following. Ideology has the typical operation in most of simply their repetition of tenets/dogmatic following. Only a relative minority actively invent new ideological stuff (more harmful sorts like Ayn Rand or in the populist political instance Trump for example, who can invent entirely new illusions/notions).
So, from experience (my own, before I got past A. Rand about age 19-20), it's more like just an ideology they hear and then it feels at that time more compelling than their own previous thinking. (e.g. reading Rand about age 13, she seems compelling)
It's not really their own thing, for most.
Many will outgrow such ideologies.
(btw, perhaps you should edit "humanities" in the title into the correct "humanity's")