The actual study states in the summary that it's the cardiac protective improvement that reverses, not that you're worse off for having taken a GLP-1.

So yeah, when you stop taking something that protects your heart and kidneys, it stops protecting... your heart and kidneys.

There's an increasing body of work that indicates that long-term GLP use (initially higher doses for weight loss, then tapering down) retains the cardiac and kidney benefits and can actually lead to additional weight loss.