Hmm... you're right on the matter of mage supports poking primarily with spells, but Ori is much different as her poking power is around 30% auto attacks and 70% skills. As an Ori support, your core goal is to keep the ball near or on your adc while you can orb walk poke. I've done this on many occasions and it is insanely effective. It might not zone, but it will whittle them down for sure.
The thing about Ori is that she is the only mid support-like champion whose build path and role changes vastly depending on the role you put her in (mid/support). As mid, she builds burst and damage while as support she builds utility (which does not necessarily include AP items).
Ori's bread and butter as a support is not a single move. That's the thing. Her bread and butter is essentially her ability to micro manage her skills reliably at a long range while incorporating her passive through orb walking/autos.
I used to think that she should use her skills in lane like Lux or Brand too, but that quickly changed when I tried utilizing better movements/positioning along with orb walking/autos. The latter was much more effective and worked very well with an ADC who isn't an idiot.