There is a huge assumption that Sogdians were Zoroastrian... Islamic evidence assumes that they were polytheistic, Buddhist or otherwise varied other religions (some may have been Zoroastrian, but a slim minority if any). The nobility who ruled lands near the region of Sogdiana, were the ones who reviled the Persian religion of Zoroastrianism. Such was their hatred that when Bahram Chobin rebelled against Hormizd IV and Khosrow II he insulted Ahura Mazda completely and said that he was there to shame the religion of Khosrow II and 'his god' (Ahura Mazda). When Vitstahm Isphabudhan rebelled some time after Bahram, he stated that Khosrow should know his place as of inferior lineage, that his ancestor Sassan was a poor peasant. Sassan and his children, were priests in the region of Persia under the Arsacids, to the god Anahita, a precurssor to the Zoroastrian religion. In essence, the noble was saying that the high priest, thus a place among the Zoroastrian or proto-Zoroastrian religion was a peasant and of lowly stature, compared to his nature, a descendant of the great mythical kings of Iran, endowed by the great gods since time immemorial.
The Sogdians were also not culturally Persian until the Samanids and the general Islamic rule entered the region. It was a domain of Scytho-Tocharo-Sogdians who practiced sedentary life supplemented by periodic nomadism and long-distance trading. It has very little similarity to sedentary Persia (as in modern southwest Iran).
I admit that I might be anachronistic in my assumptions on the Sogdians. I'd assume that since they were very proximate to the Sassanids, and that Sogdians seem to be the obvious route of transmission of attested Zoroastrian communities in China, they'd have a sizable community of that faith or something similar (all manner of Iranian beliefs). Like a lot of Central Asia, they had their Buddhist, Christian, and Manichaean communities. But certainly their development would continue as OTL with or without Islam.
If Zoroastrianism was the religion of the culturally 'Persian,' then we would expect the Aremenians to have been so prior to Christianity, yet it was not so.... They were practitioners of Iranian polytheism and generally pre-Zoroastrian religious systems that were en vogue until the rise of Islam. The Kushanshahs seemed to completely disregard this supposed culture of Persia, despite ruling the supposed homelands of Zoroaster. This is a very clear-cut issue in my opinion, but one that is hampered by modern Iranian nationalism, Sassanid distortion, Persianism from the Western world (denying other Aryan traditions except that of Elam-Persia), mass media through strategy video games (especially Crusader Kings 2 and the recent Imperator Rome) and the subsequent Islamization of Persia and thenceforth conflation of Iran = Persia (in fact there is nothing the same, the noble houses seem to have held Persia as a despicable place of lowly people; while the Persian Sassanid royals, viewed the exterior lands of Persia, as lands of impiety and fraction).
You have a point, but how do you fit Armenian gods Anahit (Persian Anahita) or Aramazd (Georgian Armazi or of course Persian Ahura Mazda) into this? It seems evident there was since Antiquity plenty of influence from Persia in religious practices in surrounding areas, which might prove fertile ground for some powerful Persia-based empire's religious reform.
There is no such thing as folk-Zoroastrianism, this was just a system by which the Sassanid royalty could negate and erase the nature of Iranian religion. It is akin to a Christian conquered Middle-East, referring to Islam as some sort of folk-heresy of Christianity or Jewish thinkers called Christianity a deviant folk tradition. Folk traditions are either just a general description of traditional polytheism or a reference to a situation where there is a clear religion and the peasantry are of such an opinion that they cannot tell the difference between where their religion begins and where the custom ends. So they mold the two together and reinterpret meanings. If anything, it was the Sassanid royalty who was practicing this, attempting to appeal to the nobles constantly, whilst reviling their polytheistic ways. This too is proven by Islamic accounts after 700, they mentioned that few if any of Iran is Zoroastrian aside from priests, everyone else practices other faiths; even the more Gnostic varieties of Zoroastrianism outlasted mainstream Zoroastrianism in Iran. Once the head was cut, it was in free fall...
I'm using "folk Zoroastrianism" as a synonym for "Iranian polytheism" as opposed to state-supported practice. I'm aware that it's somewhat imprecise (since Zoroastrianism as we know it owes a lot to Kartir and the post-Islamic developments), but as you noted, I've been using imprecise terminology and equating "Zoroastrianism" to "Iranian polytheism" since a lot of Western sources do so. I suppose it's like using "Hinduism" to describe to myriad of Indo-European-derived beliefs in the Indian subcontinent.
I'm defining it as the meat you get which is found roasting vertically on a spit.I think it depends on the definition of kebab.
Are we just using the skewered meat one common to Anglophone countries or the more generic grilled meat definition?