That's the story/narrative that's easy to sell, but the reality is that Tesla fell because they failed to justify their lofty valuation and growth slowed. The stock was already tumbling long before Elon selling specifically to fund his twitter purchase. Going even further beyond the narrative, he's always been a big seller of his tesla stock:
Space X is his real passion/baby and he uses Tesla to fund it. Him doing similar for Twitter is nothing new.
He was selling similar amounts in 2021 and the stock still managed to go up, why is that?
This is the reality, Tesla quadrupled their earnings between 2020 and 2022, everyone got over excited and started pricing in future growth at the same rate. Then revenue growth ground to a halt and the rest is history.
The funny thing is that they've stared growing earnings once again but the stock is no longer wall street's darling so the stock is largely doing nothing while remaining locked in a downtrend. The market loves a hot new thing to pump and that thing is now Nvidia so it will get all the attention as long as the growth story is still intact. That is, until the next one comes along.