I think it’s pretty much obvious this buff is really a nerf to tendrils (in fact deck is outright killed), which mage rarely if never build around.
One deck that isn’t used now that is technically buffed is any deck that wants to use orb as the curve is teeny tiny bit less clunky.
This one does hurt mage more, but similar to above I think it’s more about nature shaman. Along with all the other nerfs to nature shaman, that deck might as well be the closest thing to being killed like tendrils.
Note that the fact shamans got hit so hard kills the old mage whine about how other classes get away with doing things mages did (but got nerfed for).
Don’t play wild so I won’t say more about waygate, but I will say that hey, Zarimi got nerfed too.
For standard, while mage really isn’t buffed a lot, but the fact that other classes got nerfed (to their best decks, they might receive buffs elsewhere) should result in a bigger net gain.