If it were merely "asking for access to some [...] information" why would it need to be "on [my] behalf"? I don't plan on accessing that info myself more often than once in a blue moon when i need to update something... Maybe it's on behalf of my browser?
The site presenting the dialog does seem to be www.mediawiki.org, but if i grant any of the rights you linked to, it apparently could then "Edit pages protected as "Allow only autoconfirmed users" (editsemiprotected)", or "Edit pages (edit)", etc... Why would i allow any of that? There should be a "read profile data" level of access that DOESN'T allow any action. In fact, there should be a "Read only a profile token that doesn't contain anything other than a unique identifier for my mediawiki id", and i would set up my profile on phab to anything i want, regardless of what my MW profile says.
PS Apparently, an OAuth-rights-request dialog could show what actions it's asking for (even though an "interact with pages" doesn't seem to be in the current list of available rights)... Phab isn't, so it makes me wonder what's it trying to hide.