We have already tried that in human history, it's called communism. No one is allowed to take private profit, everyone contributes to the best of their own ability, and everyone consumes according to their needs. It should be utopia because there is no wealth gap and wealth is maximally redistributed. Which is exactly what taxation is designed to do, only to the most extreme.
And I think everyone will agree with me that communism is a miserable failure. The rich may not leave physically but mentally they are checkout -- not willing to work as hard or take as much risk. So the answer is yes, if you tax them, most certainly they will leave physically for haven with lower tax, all things being equalled. Or leave mentally.
But not all things are equalled, so you can still tax them at a somewhat higher rate provided that you can provide other incentives. But still, too much tax will make it more likely for those who are able to to leave. This is almost an axiom.