I have edited a lot on Wikipedia (>100k edits over several years) and can confirm that it is against the editing guidelines to add guidebook style identification information such as ID tips to Wikipedia pages. The WP:NOTGUIDE policy (here) deters the addition of anything that resembles a guidebook or identification key for articles. Additional project guidelines (birds, fish, plants, etc) have examples of species article layouts that encourage the addition of morphological descriptions that do not reach the level of a guidebook.
ID tips and links on BugGuide are great, but do not extend beyond arthropods and are limited only to North America.
The “best” location for ID tips on iNat has been discussed a lot in the past and many forum users would like to see an editable identification guide near the “Similar Species” and “About” tabs for each individual taxon page.