I almost always welcome such initiatives because the new team member brings a fresh perspective and is unencumbered by our existing knowledge. And they don't have that many responsibilities yet, thus they can focus on the code itself. But good test coverage and thorough reviews are necessary to do this.
No don‘t get me wrong. I see this as well and have an inner fight when the typical: Let’s clean this up PR pops up. What I mean are changes that have no real value other than a change from Person X in file Y. Yes one can rename tons of methods and variables. But maybe these names stem for a reason. I have one example where the variable names where generic in nature and the change request renamed them according to the concrete implementation. You can argue back and forth about this :)
