It's only an Oxford comma if it's from the region of Oxford. Otherwise it's just sparkling interpunction.

That's the topic of the next debate.

Correct, no comma before the last element if it is preceded by a conjunction (e.g. "et", that is "and" in English) in French

I mean, reading that sentence, it certainly wouldn't surprise me if they omitted it just to spite the British.

Yes,

Centerists will always attack the left rather than the right. They are actually right wingers that don't want the social stigma that goes with admitting that you're right wing. Once the progressives have been killed off by the right wing, the liberals will take the mask off.

The lot of them are cowards and the left is a whole lot less scary than the right, since we don't go on random killing sprees frequently.

Yeah, I think going toe to toe with the far right once again was always Macron's plan. This is the foe he's familiar with, against whom he won before. The short deadline for the anticipated election was probably to keep the left from organizing, as to not disturb their duel. But it backfired when the left immediately formed the Front Populaire. Now he's nervous. The polls give his party third place, so he's playing for second. He thinks if it's the centrist against the far right, the "barrage vote" will save him once more.

What's shocking is the extent to which they go to demean the left, and the amount of media that help spread his baseless accusation. Everyone knows at this point that the center will lose, so they're choosing who they'll lose too. They maybe think it'll erase the left and let Macron's clan be seen as the alternative to fascism during the next presidential elections...