It's a bit of a silly situation / discussion really. Ultimately, we create(d) these numbers to help us calculate things and nothing else. We randomly assigned a value to an object and gave it a name. Saying "well the object we once based it on is now different, so the value is now different too" is just making life difficult for yourself.
For example, we gave earth going round once a value and called it a year. So, we made a calendar based on that, and decided our age based on that principle as well. Let's say we suddenly find out by some miracle that the earth actually moves twice as fast as we thought, or something impacts it and changes it movement speed; does that suddenly make us twice as old as before? No, because we simply chose to assign a value and name to it, nothing more.
I understand why for scientific purposes the exact number needs to be correct, but arguing that because the object we based the kilogram on has changed, so should the value of the kilogram is, in my humble opinion, just silly.
