I'm really, really certain that in no single country on the whole planet it is by law that any company must take money for updating software of anything.

You can sell software. You can give away software. You can sell devices. You can give away software for devices. A computer is a device. Some software is on subscription basis. Some not. Some is free.

Companies are completely free to do with their software whatever they like.

Apple can charge 39.999,00 $ per IPod Touch update, or can send you the software free with a coupon for a free Mac Pro maxed out configuration.

It is Apple deciding, on their will if, - or not -, to charge for anything.