Also, if outside of America, you probably would have a strong case for getting a full refund on the product if they did this.
It’s not (to my knowledge) a type of case that’s been specifically tested in court, but I think you could make a strong case that under Australian law, being required to agree to a new TOS that wasn’t there when you first purchased the device and which you don’t agree with would qualify as a “major problem”. The description of a major problem includes:
is very different from the description or sample
can’t be used for its normal purpose, or another purpose the consumer told the seller about before they bought it, and can’t easily be fixed within a reasonable time.
And when there’s a major fault, you as the customer are entitled to a full refund or replacement “of the same type of product”.
Unfortunately, if you did this, it would be the shop that sold you it that takes the hit, because you have to go to them to get the refund, not the original manufacturer.