Feature summary:

If a page is moved together with its talk page then the initial rendering of the new talk page should be able to detect the non-talk page.

Use case(s):

It came up here: https://en.wikipedia.org/w/index.php?title=Wikipedia:Village_pump_(technical)&oldid=1303596339#Broken_banner_shell

An article was moved together with its talk page. The talk page move was logged a second later but the talk page could apparently not detect that the article existed. This caused WikiProject templates on the talk page https://en.wikipedia.org/wiki/Talk:St_Julians_railway_bridge to add incorrect categories until the talk page was edited three weeks later. It also meant incorrect data was displayed for three weeks at https://en.wikipedia.org/wiki/Special:PageAssessments?project=&namespace=0&page_title=St+Julians+railway+bridge.

Could something be done about this issue? E.g. delaying talk page rendering a little after a move if the non-talk page appears to not exist, or adding a job queue task to reprocess the page later?

Benefits:
It helps editors if the correct data is displayed on talk pages, in categories and elsewhere. There may also be article templates which change behaviour if they think there is no talk page.