You generally don't want to confirm leaks as being true, so you'll either not say anything about it (this was an internal memo, not a public post) or you'll say something along the lines of "These things are subject to change and don't reflect the final product"
The real reasons why the wiki is no longer official (because everyone seems to have their own version of events) is here, but here's the cliffnotes:
Mojang/Microsoft's legal team contacted them notifying them that the contract they signed with Curse in 2011 is being terminated (probably because Curse was no longer the owners after being bought by Fandom)
As a result, all of the official logos/artwork/anything copyrighted by them could not be used legally.