So before I start telling EU citizens to sod off for dragging the word “monopoly” into these discussions regarding Facebook’s or any other company’s monopoly status within the EU which by your account doesn’t seem to have the means to even determine that nor a body of law built up around the concept, do any of the member nations have their own anti-monopoly laws? Or have all of their own competition laws up to and including any real or hypothetical antimonopoly laws been preempted by the TFEU?

The EU has competition law (like the USA to be honest). Competition law is a lot broader than simply being against monopoly which is why I don’t understand why you mention monopolies. Monopolies are an extreme form of disfunction in competitive markets. There are a lot of emphasis on market dominance in the EU law which is itself a concept broader than monopolies. A monopoly is necessary a dominant player so would fall under all the provision of article 102, yes.