I have no idea. However I will say that neoliberalism or even social democracy is very different from the views espoused by Communists pre and post Marx; as Marx said, the theory of Communism can be condensed to one statement: the abolition of private property. However as Badiou notes, there is the Communist Hypothesis[0], that is, the idea of these subversive movements which aim for liberation and the removal of our class structures - these may not necessarily involve the full abolition of private property.

I do not consider neoliberalism to be a modern Marxist invention, though I can't claim to know about its history, and of course hitsory is extremely important to reveal a movement's origin and aims. My reasoning is from the idea that neoliberalism supports private property and what Marxists see as a class society. It does not aim for the abolition of these classes, but rather its stated goal is to acheive development within the capitalist system.

In this way, neoliberalism is identical to social democracy in its overall aim - it works within a class society to try and bring better conditions, though people frequently criticise neoliberalism as being uncaring of the poor, the Marxist would say a similar thing about social democracy.

For a read by a thinker inspired by Marx, I've heard good things about David Harvey's A Brief History of Neoliberalism. I have not read it, so I don't know if I should recommend it, but since you mentioned modern Marxists, and he is one, it may be of some use to you.

[0] https://newleftreview.org/II/49/alain-badiou-the-communist-h...

We may be assigning motives and anthropomorphizing far too quickly things that are just secondary environmental effects, i.e., emergent behavior.