But yeah, gaining sentience is an odd thing to have happen in the middle of Quintesson occupation, for a range of reasons. It's not quite like Skynet where machines gaining sentience is the beginning of the end; here sentient robots are meant to be ones we see the story through.
The Sunbow continuity's backstory is very much an "AI rising up" story only we happen to be seeing it through the eyes of, and are sympathetic to, the AI. They very much do "gain" sentience in the middle of the Quintesson occupation, though even occupation isn't the right word. Cybertron was a planet-sized factory they built.
It's shown very clearly that the Quintessons began making "consumer goods" and "military hardware" robots to sell before deciding to imbue their creations with "simulated AI" so the robotic creations could manufacture themselves.
Over time the Cybertronians gain sentience as their "simulated AI" evolved into full on artificial consciousness, and they rebelled.
So in the context of the G1 cartoon it's not "demeaning" to say they "gained sentience" as KingSwoop claims. It's an actual description of events.
I prefer the notion that Transformer society existed pre-Quintessons, which presupposes sentience.
That's valid, I myself go back and forth on how I prefer it. The Primus/Unicron mythology that the Marvel G1 gave us that grants us a Cybertron that was its own civilization before they even met the Quintessons is far richer if you want to develop mythic stories.
There is, however, an appeal behind the idea of robotic life coming from an organic creator and growing and evolving to the point where they lost the memory of where they came from, and that creation story being tied into concepts such as the technological singularity, trans-humanism, etc... And in that direction, well... the Quintessons are as good as anyone else to pin as the "creators"
But again, your preferences are totally valid. I'm just explaining that in the Subow cartoon specifically the Cybertronians did gain sentience from a pre-sentient state.