Yes they do, quoting for example "we should take that anti-religion energy and focus it on class struggle instead. Once we, the proletariat, control the state, we can suppress the power that religion holds over society."
It's basically class reductionism and also opposing at least the reactionary religious institutions is a part of class struggle anyway, not to mention opposing the usual religious rhetorics of class solidarity. And both will be framed as opposing religion anyway, so we don't really have to hide marxist materialism.
Of course, in the context of thread, Quran burning is definitely not any of this, just a useless juvenile demonstation and provocation (which also more often than not comes from the fanatic christian circles).