I don't need to waste my time but you amuse me. For fun I'll only use the source you provided.

if they’re already leaving because of high taxes

Citation needed, the source you linked says they're leaving because WFH became popular during the pandemic, not because of high taxes.

The chart shown is for earners making more than 200k, whom are not the target of the millionaire tax.

The opinionated article then goes on to say the largest block of folks leaving are age 55-65, and they're mostly moving to Florida. This is not a new trend, but I'll admit I'm not going to dig up a source to prove that it's not new. That being said nothing you've cited shows that retirees are leaving because of the millionaire tax, only that FL doesn't have state income tax.

You're free to draw whatever conclusions you want from the data provided but I don't see how it's at all relevant to the post.