I disagree they're taking more power, what changes is the expression of power. During the good times, there's no need to repress in overt fashion because the working class buys into the narrative. So, some freedoms can be allowed because workers are docile. When there is an economic crisis, the worker unrest starts, and that requires more direct measures to put down. However, the power was always with the ruling class.
Other systems such as feudalism share aspects with capitalism. There's no contradiction here. One system evolved out of the other, and necessarily has shared characteristics as a result. Just like socialism retains aspects of capitalist society as well.
Meanwhile, arguing that these points will somehow be co-opted by the right-wing is a stretch.
I don't really see anything anti-Marxist in explaining how the fascist narrative works. Madeline Pendleton clearly has a firm understanding of Marxism, as is clearly evident from her other videos where she talks about theory. The goal of this video was to focus on the narrative that fascists use.