WK are apparently working on something to replace it, but no one’s really getting their hopes up since they don’t have the greatest track record with implementing features, etc. they say they will
In the meantime, there’s this userscript that was made to somewhat replace it:
There are also the mobile apps (Smouldering Durtles on Android and Tsurukame on Apple) that still have review summaries, but Tsurukame at least only shows wrong answers.