You're 100% accurate on your definition analysis. "Theory no more" - this would be the accurate conclusion to draw and verbiage to use. People are brainwashed into redefining what words and phrases mean from propaganda being beaten into our heads for decades. I don't think everyone is controlled opposition or "in on it" so to speak.
A more accurate basic definition is:
Conspiracy theory - a suspicion and idea surrounding two or more people planning something in secret to benefit themselves - generally to increase their wealth, power or control.
We have all been brainwashed to associate the term "conspiracy theory" with meaning a fictional or outlandish narrative. People conspire all the time (you can be legally charged for conspiring sinister events) - just because there is a theory about someone conspiring events doesn't make it fiction. Facts and evidence lead us to know whether the theory of the conspiracy is valid or not. This "conspiracy theory" term has been drilled into heads of people since the Warren Commission (JFK assassination) and used by the CIA controlled media to effectively discredit and shame anyone who exposes their lies - still effective more than a half century later. They don't need to provide any facts - they just label their opposition a "conspiracy theorist" and the sheep go "see I knew it was bs!" and they never even think to look deeper. It's a literal psyop most of humanity has fallen for.