Why was the English message removed from the messages' pages?
Fragment of a discussion from Support/LiquidThreads
We changed navigation, and consequently the source message was removed. Currently Niklas is prototyping a replacement. Meanwhile you can use the review mode of Special:Translate.
Thanks. Please note that I use Special:Recentchanges, because the review mode seems to include only messages that were not committed, not necessarily not reviewed (and not necessarily includes all the messages that were not reviewed).
I suggest that you subscribe a recent changes feed for your language and make your feed reader download the whole pages. That's the fastest way to review currently.
Nike