Does it mean that none of the judgements are canon just because that is the case with one judgement?
We don't know. That's why the thread was made. We don't know if Xerath is the new standard where they abandoned "preserve character identity", a fluke caused by bad communication, or a rare case of biting the bullet because some champions need to be reinvented like Sion.
When Trundles lore got retconned did you instantly assume that every other piece of lore is no longer canon?
I didn't play or follow the lore much during that time. What I remember from the old forums though was that people were upset on how many champions were retconned to be a part of the Freljord conflict. Trundle was the most controversial. In hindsight though, it was a sign of how detached Riot had become regarding the League until its retcon.
I dunno why everyone thinks that suddenly nothing is canon anymore when plenty of the stuff in many lores can stay the way it is(and many lores were already made with the retcon in mind),riot has always retconned certain stuff,why should they now suddenly retcon everything at once?
Plenty of things can stay the way they were, including the League. Except for possibly the Harrowing, I haven't seen an event or lore development that contradicted the League's existence. That's a part of what people have been arguing for months. If Riot doesn't want to make something canon, regardless of their reasoning, they can retcon it. We knew some things were getting retconned, but before the League retcon, we assumed it was retconned with the League in mind. That's a reason why this thread was made. Will they keep the rest of the judgments in mind?
We're afraid of their sudden retcons because so far they have shown how they're going down a slippery slope.