Assange is currently under extradition trial in London, so this is probably being mentioned to make the case that the extradition request is political in nature as opposed to actual legal interest (no personal take on validity/chances of success, that just seems like the play).

I'm not sure about the reasoning for why one would do this, but it's the same person that took a gamble to get dirt on Biden and got impeached over it, so probably shouldn't approach it from a place of pure rationality. It's terrifying that Rohrabacher was a part of this though, and really skews my personal take that nothing about this was above board.