Melee push - how bad did they nerf?

[Stonewallx39]

I was in group the other day and mentioned I’d reposition the casters so we could push to help prevent healing. One of my group mates reminded me of a somewhat recent (last 12 months?) patch where melee push is less likely to interrupt casting. I knew of the patch and it’s effects but he was of the opinion that melee push is a waste of time and only bash/stun/etc. would affect stopping casters.

I know melee push does have less effect (very frustrating soloing clerics on my monk) but is it completely useless? If there a floor for effectiveness say you need 3+ Melees/pets coordinating to be successful in a group and 10+ on tougher mobs?