Is it "over"? I mean, yes, at this specific moment in time, the game has been utterly flattened by the ascendance of the three point shot. But as I noted in a separate thread, it's unlikely to remain this way. The NBA is very sensitive about how their brand is viewed and understood. And though they sometimes react slowly, the league office is generally unafraid to shake things up. Just consider the play-in format and the in-season tournament.
As greater numbers of fans, pundits, players, coaches, and front office personnel continue to express displeasure with the "state of the game" in this era of three pointer excess, the league will alter its course and make changes to the rules. It's not like this is an unsolvable problem. Will the NBA outright remove the three point line? No, I would expect not. But there are plenty of innovative adjustments that could rebalance the court and tilt the math away from the three point shot, and the league office is no doubt discussing some of those innovations. I imagine we'll see at least a couple of them implemented within the next five years or so.
And while that obviously affects nobody's coaching search today, it is hardly a given that having influential coaches with stylistic variance and particular systems on either end of the court is "over".