I think that Wanikani won’t go that route because a big part of their userbase doesn’t even get to reach level 60, so adding more content wouldn’t necessarily mean more users/more activity. Heck, I’ve been in here for 3 years and only know 4 people (including me) that are close to burning all items.
Besides that, the technical work it would be required to do that would be significant and better spent in other features that will be used by the current userbase.
I also think a big part of the community that SRSs vocab appreciates the freedom of being able to build things on their own way too, which would be in some way limited on WK due to the structure of WK itself (how lessons look like, information displaying, etc). Not to mention that Wanikani praises themselves (and they should) with in-house content (like the radicals, example sentences and mnemonics), so that would take away from a big selling point of theirs. No way would the community be able to build quality content like WK’s for free. I know from personal experience how hard it is to work on decks. I’ve spent 1500h on improving a version of the well-known Core 10k deck and I’m still only half done. I could have read 1000 manga volumes in Japanese instead.
Have you checked kitsun.io? Its user-friendliness is much closer to Wanikani than Anki is and it’s exactly what you’re describing. It has dozens of community decks available for you to learn. You also have Jisho integrated within the website itself so you can literally search for a word in the dictionary and add it immediately to a deck. The lessons and reviews system are closer to WK’s. However, decks don’t have a level system (a planned feature however - and it does have an overall level system for all decks). It also doesn’t have the whole unlock system (but also a planned feature). It’s a paid to use platform with 14 days of free trial though.