We won’t be getting the “Sell all junk” vendor option in tomorrow’s patch 10.1.5! Blizzard announced a delay for the feature due to some last minute issues coming up. We should be seeing it in patch 10.1.7 instead. 

Sell All Junk (Source)

Due to some last-minute issues that have been found regarding the “Sell All Junk” button, this option will not be released this week with Fractures in Time and will instead be targeted for the next content update.

Thank you for your understanding.