Keeping in mind that I don't know the ins and outs of UK politics, is Biden likely to have any influence on Johnson/Tory policies in light of Brexit and the need for trade policies? Or is that moot now that UK and EU have come to some sort of trade agreement?
One of the pillars of Brexit, albeit utter bollocks, but used to shush the masses, was that all the UK trade with the EU would be replicated a million times over by a trade deal with the US. It was one of the thorns in the side of the UK-EU negotiations, as Brexiteers used it as a reason to refuse to accept anything. It was why they felt they could rip up the WA and GFA with impunity - after all their mate Big Bad Donald would see them alright.
You can sense the shift in policy the moment Biden won.
Come January 21st, you won't find a single Tory who wasn't full square behind Biden.
But in this case I do hope Biden does bear a grudge - after all he's allowed to. Not against the UK. Just against Boris, personally. And I hope that makes for some very very uncomfortable photo opportunities as well as some plain speaking.
The UK press obviously won't dwell on British history. But I hope Boris gets caught in a pincer movement where Joe Biden and Kamala Harris reminisce over their experiences of the British Empire.
To return to your question, a trade deal with the US would have been useful to push the rhetoric of Brexit, but as an actual thing it would have been shit and not really worth that much to the UK as it's nowhere near the size of the EU market.