The whole vin tag thing is a grey area. The law talks about being illegal to remove it but what about cases like this when it's attached to a dash that's being restored or replaced, or the vehicles where it's attached to the drivers door and the door needs to be replaced. Doing a quick search online it seems like for newer cars car manufacturers provide a service that you can get a replacement vin tag from them, some of the forms to request it are even on the nhtsa website.
One thing that comes to play is with a replacement there's always going to be people out there to criticize it and rightly so. If you're looking at buying a car and one has a vin that's never been touched and another one has been replaced or looks questionable you know what car has a higher chance of getting picked.
I also ran across this website which has vin tags and the various other labels. Which might be a handy source for restoration purposes.
https://www.alumaphoto-plateco.com/products/vin-tag-replacement/vin-tags.html