Nobody said guarantee. Warranty.
And as was said already look under Features on that website I linked to it’s listed there for each brand.
Or phone a bed shop tomorrow if you are that desperate to be sure.
But you’ve had at least three different people here confirm it for you. And it’s there on all the websites if you make the effort.
It’s been a thing for many years. Just because you were blissfully unaware of it doesn’t make it untrue.
No need to get testy....