Ok, maybe it's time to say that Sundin is one of the guys writing for the magazine. Making fun of each others in the redaction team is a habit for them, most of the regular readers get the jokes immediately but, indeed, it's probably very obscure for first timers (and foreigners).

As for the French, they don't have any 'coloured' version of the situation, most of them just don't care. They've just heard about it on the news once or twice but that's it.
It's just common knowledge that we, Belgians, are leaving in a weird, malfunctioning country and they enjoy having fun about it. Even more in this magazine because there's a bunch of Belgians in the team. And Belgians are probably amongst the favourite subjects for jokes in France anyway.

I'm Belgian but I live very close to the French border, in the traditionnaly most 'French' part of the country (Picardie), and I can assure you that most French didn't even know Dutch was spoken in Belgium until something like 10 or 15 years ago (don't even talk about German). When a Flemish person was appearing on French TV, that person was speaking French with a funny accent they used to call 'the belgian accent'. So they're far from grasping the whole linguistic and geopolitic situation (why would they care anyway?) and this comment was really without any political implication. It was just a joke...