Rune drops haven't changed in D2R. Cows and Chaos are one of the best places to farm for those but if they drop frequently? Definitely no.
It takes me an average of 5 hours to find a HR at Cows at P7.
The last three hours in the Tournament didn't provide any rune so I kept farming when it was over hoping one to drop soon.
It didn't drop that soon but at least it's a Lo which hasn't appeared for a long time now...
Once again, I am taking a break from Cows hoping the devs will surprise us with a patch (LOOT FILTER) soon.