When we were there a month ago the weather was similar to the current forecast. At the hut it was colder but no real issues as I never used my puffy. The climb was a different story. What started out as almost warm temps (high 30s) turned much colder on the glacier once the wind kicked up. I estimate it was in the single digits with 20 mph gusts on the summit. I had plastics and my puffy along. I never used the puffy, only my softshell with a wind shirt layer. You can't tell what the weather will do that high up with a lot of confidence. I've used my puffy on other trips to Orizaba and was thankful that I took it. Hope this helps. Cheers!
Both times I climbed Orizaba it was with leather boots and multiple layers of fleece under Gortex. I had good weather each time so I was warm enough while we were climbing. Last time we were there we arrived at the crater before dawn. We waited for the sun to start coming up before climbing the last bit to the summit. We got cold while we were waiting but nothing serious. I would have put a down jacket on if I had had one with me. On the descent I got hot with the sun on the glacier.