If you head to a deleted revision with enough rights ([[https://deployment.wikimedia.beta.wmflabs.org/w/index.php?title=User:Daimona_Eaytoy&diff=9504&oldid=9499|example on BC]]), a message is shown asking if you want to actually view the diff. Clicking the link shows the diff as promised, but not the page text ([[https://deployment.wikimedia.beta.wmflabs.org/w/index.php?title=User:Daimona_Eaytoy&diff=9504&oldid=9499|example]]). It didn't use to work like this, and you would normally see the actual page text. I guess this is some sort of regression, but I haven't found what caused it.
Also, the same thing happens without diffs. Opening the page of a deleted revision ([[https://deployment.wikimedia.beta.wmflabs.org/w/index.php?title=User:Daimona_Eaytoy&oldid=9504|ex]]) and clicking "view this revision" results in an [[https://deployment.wikimedia.beta.wmflabs.org/w/index.php?title=User:Daimona_Eaytoy&oldid=9504&unhide=1|empty page]].
On my wiki, where I have MediaWiki master from August 28th, this doesn't happen.