Bring it on!
It is nothing more than a threat to the factions within the Tory party. Even if the Lords accepted this new legal statement/law or whatever it is, it does not change the how the judges deemed Rwanda. There was nothing that said because the UK said Rwanda is not safe. It was stating Rwanda is fundamentally not a safe place to send refugees who are waiting to be processed. Having the UK parliament declare something other than it is will not change that fact.
He is basically giving them (the Tory crazy bunch) a head’s up. Look I will look like I am dealing with this. You can use this to appease your batshit crazy supporters. The alternative is an election.