Sorta. It's very materialist. It treats economics as the foundation of historical development. Interest groups attract people based primarily on material concerns. Classes hence struggle against each other (afaik without scripting) and create alliances with other classes and do revolutions. What its really missing imo is the environmental aspect to be truly 'marxist' tho (the 19th century is when concerns about "what happens when we run out of fertiliser/trees/fish/etc" started really growing as a result of unprecedented extractivism, and these are recurring concerns in Capital)
I wonder if it is because with the game becoming less popular again
A lotta the reason people keep talking about marxism in vicky3 is because the devs of vicky3 outright said they uesed some of Marx's economic theories because it makes for good game design.
Also something something reality has a marxist bias.