Vayne has been at the bottom of the ADC pool in both League of Legends casual play and also the professional scene. As a result, Riot Games decided to give her a massive buff in the PBE server, and if the buff ever goes live, she will definitely be back at the top of the pick and ban list and reclaiming her spot as a tank shredder.
Riot's intention of making her a viable champion to pick again. However, the bad news is that all of these changes were reverted back to the original effects and stats. It's still a good thing to know that Riot still has Vayne in their minds.
Hopefully, Vayne will still receive her buff in the PBE 7.17 cycle or future patches, but maybe tone it down a notch so that it will not be as overpowered as the ones stated above.