Literally the first statement before it launches into the actual game related info is that it is a copy from an older source that did not survive the overhaul of Blizzard’s website.
It also states the Troll version of events, and then the Night Elf version of events. If however you wish to check ‘Night Elf’ on Wowpedia, it states the lore version of events, with current canon sources including the Warcraft Chronicles.
Always go with Wowpedia, because unlike a Wiki, it cannot be altered by just anyone, and always provides links to the lore source.
Seriously, type in Night Elf and scoot down to the bit where it details the origins of the race. They were Dark Trolls who moved to the Well of Eternity and became Kaldorei. That is current lore fact.
Fact: Definition; “A thing that is known or proved to be true”
You can’t have a False Fact. Not unless you want to twist the definition of the word Fact, to mean something else, in which case it no longer is a Fact by definition. I know Trumpism coined lots of phrases like ‘False Facts’ and ‘Fake News’, but then Trump is an intellectual pygmy who is not very good with words. He used the word ‘bigly’ (Which is actually a real word!) without realising that he had just called himself ‘swollen and blustering’, and we also still don’t know what on earth ‘Covfefe’ means in his head, but he stands by the word.
Never use phrases like ‘False Facts’. It is a Trumpism and not a correct phrase.
Besides, when I state something, I make a point of saying “Now this is just a hypothesis” if it is my opinion. That is because I can separate my subjective opinion, from objective fact.
So I can’t answer ‘Why?’
As I never do.
But yeah, look up ‘Night Elf’ on Wowpedia and the sources, you might find out some interesting things about the race of your posting Avatar.