I don't get this argument. There is no new standard here. This is just a tool that says, "is there anything that looks like a mathematical/statistical mistake"

I don't get this argument. There is no new standard here. This is just a tool that says, "is there anything that looks like a mathematical/statistical mistake". The expectation that a paper's calculations are correct and error free is one that has always existed. There is no "thinking of the day", there is just mathematical correctness or not. At most you could argue that we might learn that some thing we thought mathematically true is no longer so, and warrants us reviewing papers where it had previously been used, but that is not the case here. It is not unreasonable to hold published research to the standard of correctness, and if a paper contains errors within its calculations these should be fixed - regardless of when or who published it.