Recently the way to create potion-tipped arrows was changed from shooting arrows through a lingering potion cloud to just using the crafting table instead.
So now that they are actually craftable in the Crafting Table, one would expect there to be a statistic to track this, much like there is stat.craftItem.minecraft.spectral_arrow and arrow.
Just a minor thing, but would probably be an easy fix.
Example command
/scoreboard objectives add test stat.craftItem.minecraft.tipped_arrow
Fixed in 17w49a. It's called minecraft.crafted:minecraft.tipped_arrow