I don't think you were click-baited, you don't even have an all metal hotend...
Your first clog after a year is actually kind of an anomaly with the FLUX, but you are making your oiler sound like a Lucky Bowling Shirt... A year of printing can and probably has led to plenty of wear in your hotend, especially the nozzle itself and the internal PTFE tube.
To answer your other questions, all metal hotends do not have the tube, so no, the FLUX is not an all metal. Not even close. I may actually have the only all metal FLUX toolhead at the moment and this article definitely did give me some good clues, as it did not occur to me that I need to put together a whole new settings group for it, but it makes a ton of sense and in testing I am seeing exactly what the author described. Reducing retraction... yep, seems obvious now.
As far as maximum retraction on the FLUX, I'm not sure, it can go pretty far and pretty fast. I think the most I've ever pushed it was around 12mm at 60mm/s though and I doubt that was making it work at all, but I also can't imagine why you would need more than that either. (Even that was overkill, I had wrong temp and movement speeds)
These days, I barely ever touch retraction, it's usually somewhere around 7-9mm at 30-40mm/s I think. That's with the standard FLUX toolhead.
Changing that might be just the thing I have been trying to figure out with the all metal hotend.
Oh, and as far as oiling, the latest research I have seen is that as long as it isn't messy, there may be some usefulness to it in terms of helping the nozzle (not the whole hotend) to a very tiny degree, and possibly some changes to part strength with organic oils. I've been looking for more objective testing but haven't really found anything good yet. I did put mine back on for a few prints with an older spool of filament and a very tiny bit of coconut oil. I can't say 100% that it helped, but it definitely didn't hurt as prints came out perfect.