It's not about Samsung's reaction or Spain. It's about EU law and retailers. In EU the seller is the one responsible for warranty issues, not the manufacturer.
So in EU you can safely throw away Samsung's warranty booklet because that warranty is voulantary in EU. The seller (electronics shop or operator if bought on contract) on the other hand MUST give you a minimum 1 year warranty. And the whole knox thing is outside of EU consumer right law. So, in short. Knox is NOT a warranty breaker in any EU country.
However if you're living in one of the "new" (eastern european) eu countries the seller might try to trick you out of your warranty.
Enviado desde mi SM-G900F mediante Tapatalk