Extradition was specifically blocked on the grounds of a particular regime he might be subjected to (to be fair, probably the only legal grounds on which he had any chance of succeeding). That leaves the US with a way out if they want to proceed with the extradition - guarantee a different set of circumstances.
If the judge had found on more substantive grounds, those would have been much more resistant to that. For instance, all the claims based on language in the extradition treaty and other international agreements failed and they failed for pretty fundamental legal reasons. English courts only have regard for domestic law and it is for parliament to pass laws consistent with the treaties that have been signed, therefore claims based on treaty language won't work.
That means that none of the claims on the political nature of his activities were upheld and those would have provided a much more robust and durable bar to extradition.