Apologies for the late update. I’ve been sick for the better of the week. Our cycle ended on Wednesday and we are on track with everything. Autocomplete for username/emails is in trunk A directory in Subversion containing the latest development code in preparation for the next major release cycle. If you are running "trunk", then you are on the latest revision. for the site-new and site-user screens in the network (versus site, blog) admin (and super admin) and the user-new screen in the site admin.
The autocomplete in the user-new screen is only available for super admins to avoid user/email disclosure to site admins. There is a filter Filters are one of the two types of Hooks https://codex.wordpress.org/Plugin_API/Hooks. They provide a way for functions to modify data of other functions. They are the counterpart to Actions. Unlike Actions, filters are meant to work in an isolated manner, and should never have side effects such as affecting global variables and output. to enable the autocomplete for the site admins. You can use:
add_filter( 'autocomplete_users_for_site_admins', '__return_true' );
The autocomplete is not available on large networks (more than 10,000 users) to avoid scaling problems. This comes from the wp_is_large_network() and can be tweaked using the wp_is_large_network
filter.
Props to boonebgorges, Japh, DrewAPicture, nacin, koopersmith, markjaquith, PeteMall for contributing patches during the first cycle. Japh and DrewAPicture will continue working on extending autocomplete to other screens in the network admin. The rest of us will tackle other multisite Used to describe a WordPress installation with a network of multiple blogs, grouped by sites. This installation type has shared users tables, and creates separate database tables for each blog (wp_posts becomes wp_0_posts). See also network, blog, site tickets.
We’ll tacke #19796 in the next cycle starting next week.