To me, it matters not whether a language is artificial or whether it has naturally developed over hundreds of years. It does matter, however, how many speakers there are, and if we can realistically create a complete and accurate encyclopedia with that number of speakers. I'd say a minimum of 10,000 active speakers is a requirement for creating an encyclopedia. Neither Klingon nor Toki Pona meet that requirement.
Although I share the POV of Erik that we do not really need Toki Pona, I must say, that this argument can't be true, sine there are just 2 fuzzy choises: eighter the languge is not importand and has not much articles (in this case their can not be much interwiki-links to that language) or it is important and has much articles.
--Ivo Köthnig