There are brand/identity dilution and confusion issues with using any of *.wiki in an official capacity, especially as canonical redirectors for Wikipedia itself, which is why we didn't start using these many years ago when they were first offered for free.

When you look at https://domains.registry.godaddy/wiki/ they explicitly market this gTLD with phrasing like .wiki is authoritative // wiki associates your site with wiki technology and Wikipedia.org (which maybe we should have chat with them about, regardless of this ticket!), which is intentionally marketing on the back of the already-implicit relationship due to the naming. If we used the language codes like en.wiki it would further the confusion to our detriment and lend our name and values to unrelated commercial sites at the same DNS hierarchical level, such as:

• https://dokkan.wiki/
• https://emojis.wiki/
• https://runescape.wiki/
• https://fallout.wiki/
• etc...

The URL shortener domain at w.wiki got locked in before anyone managed to stop it on these grounds (and one other unfortunate case is learn.wiki), but we're at least not going to spread into this gTLD any further if we can help it.