You can always rely on Harry Potter fans to add more to JK Rowlings' original texts (not to mention the movies), no matter how long it's been since they were released. The Wizarding World community remains one of the most active out there, after all.
And while there's sometimes a habit in movie theorists to interpret poorness in quality as intention (basically adding meaning to explain why a character is so badly written), one new theory on Ron Weasley that could have fit that bill is actually pretty compelling.
A new Reddit theory suggests that Ron was actually a secret Death Eater spy, radicalised unknowingly by his proximity to Scabbers over the years and playing both sides to guarantee himself a position of power no matter what happened in the second wizarding war. And far from the bumbling fool he seemed, Ron downplayed the intellect that had allowed to play the best game of wizard chess Dumbledore had ever seen. He was a genius wolf in sheep's clothing, concealing himself from his supposed best friends the act same way Pettigrew did from the Potters.
According to the theory, Ron manipulated Harry and employed "some pretty classic emotional abusive techniques":
"He frequently punishes Harry with a withdrawal of affection, lowering his status and fostering Harry's sense of responsibility towards Ron. The first thing Ron says when he finds out Harry's identity is how he wants to see the scar Voldemort gave him. He is straight off the bat excited to see his connection to the Dark Lord. And of course he stole his father's car to ensure Harry would make it to school on time second year. He quite frequently takes a lot of joy in people being tortured by spells, Harry's inflatable Aunt and Malfoy transmogrified for example and has no moral dilemma at all about having cheated to get on the Quidditch team."
It goes on to suggest that Ron actually leaves in the Deathly Hallows to find the Death Eaters when he realises that hope for Harry's victory is running low. But he continued to hedge his bets and when Harry came into possession of the sword of Gryffindor, he switched his allegiance back, knowing that was going to be the big difference in the climactic battle.
And isn't it convenient that he "learns" parseltongue from Harry talking in his sleep? The idea that Harry would have said the exact phrase needed to open the Chamber Of Secrets again in his sleep enough times for Ron to learn it flawlessly is just stupid.
Inevitably, it's one of those theories that can be disproven in the text, but it's a reading that certainly changes things, and that's always a good thing for Harry Potter.