Wouldn't Marx mock the idea of celebrating his 200th birthday as a relic from the capitalist (or even feudal) past, from an era prior to the discovery of the truths of historical materialism & class struggle, when glorifying privileged individuals was part of drugging the masses?
I think he’d only want his close friends, perhaps even just Engels, to wish him a happy birthday. All these other plebeians can worship at some other cult of personality shrine.