You know I never shipped Zutara back in the day. But I've been thinking lately about how it would have looked for the disgraced prince that's been banished for three years; who briefly returned only to become a traitor again; helped the avatar topple the current regime; and then ended the 100 year war to also start courting a girl from the water tribe. I mean yeah Zuko is likely cleaning house of all the Ozai loyalists and many people were likely exhausted by the war and glad to see it end. But still that's a populace who's been fed propaganda for over 100 years on the righteousness of the war and the superiority of the fire nation and who now has a fire lord speaking against all of it. A fire lord who seems more comfortable with earth nation and water tribe dignitaries than his own people, including his choice of a bride . In a way Mai seems like the more politically sound choice. A way to reassure the fire nation that they're still a priority and that not too much will change. Fire Lady Katara could possibly only stoke the flames of civil war. But then as Iroh said water is the element of change with a deep sense of community that holds them together through anything, and I think it'd actually be really interesting to see Katara step into all of that political upheaval and change because she might actually be the perfect person to lead them through it. And now I'm really fascinated by that concept.
There are likely to be conflicts either way. On the flip side, Zuko marrying Mai, companion of Azula, loyalist of the old regime, and whose father was governor of colonized Omashu, is likely to make a lot of people unhappy in the Earth Kingdom and Water tribes. Especially if they had reason to expect him to choose Katara. It would certainly make for an interesting story.
Oh, I like this a lot! Adds even more fun political tension. And yeah Mai would possibly not be a great choice for improving external relations, especially for Ba Sing Se as well. It's not easy no matter how it works out.