I can’t imagine Iannucci writing any kind of romance that results in Amy and Dan being a power couple. The stuff of his I’ve satchrd never has romance at all, and if it does, it’s between two characters who are never actually together and end up fucking each other over horribly. On the thick of it, the most romantic thing his characters ever do is attempt to be kind or loyal to each other for very brief periods lol. Veep is a little less mean but not that far off from that, let’s be real
Veep is a bit of a development for him, I think, in that the Dan-Amy was a longer running thread than just about any character plot he’s ever had. And, uniquely in Iannucci’s writing, they actually seem to be genuinely attracted to each other – they willingly spend time together outside of work, they enjoy each other’s company, they go to some effort to eat together – none of those apply to any pair of characters in The Thick of It, and certainly not to any of the sexual relationships. (Ollie and Emma’s sexual chemistry is so minimal it makes Dan and Amy seem like a pair of fireworks).
So, I’m not sure I’d use his previous work as a guide to what he might have written for Dan and Amy if he had been able to finish the show – the set-up in Veep is already so different that I think it’s fair to say he was attempting to do something new. All the characters are more fully rounded and recognisably human than in The Thick of It – and, while the humour is still pitch black, I think their struggles are treated far more sympathetically. I cannot imagine a moment like Amy getting nervous over a date in 2.06 or Mike’s wedding appearing in The Thick of It.
And, while their relationship is always treated as…incidental to the main action, he did devote quite a bit of time to it over the years – 2.02, 2.06, 4.04…they all take moments to pause and show us how Dan and Amy are relating to each other as people, rather than as colleagues.
Season 3 is an outlier, because their rivalry is easily one of the principal plotlines, but, aside from Dan gabbling about how Amy’s his one true friend after he has his breakdown, it is entirely driven by their working situation. The rampant sexual tension is just an additional obstacle to Selina’s team working effectively. And almost the first thing Dan says is a joke about he and Amy are going to have children together…so the subtext is never too far away from the audience’s awareness.
And the show spends so much time establishing Dan and Amy’s relationship in the first season – that they dated, that Dan is overly interested in the idea of her being pregnant, that they are competitive, that Dan likes getting her riled up – that I have find it hard to believe Iannucci never intended to do anything with it. Especially as Reid Scott that he was specifically cast for his chemistry with Anna Chlumsky, auditioning with her rather than by himself – meaning he was cast at least in part as a love interest for her.