Well, teaching it to do diplomacy is definitely the problem. Basically, training an AI to play gunboat diplomacy requires good programming knowledge and being able to make a neural network. I cannot say I know enough about what would be required, but it is definitely possible. Teaching it to play in press games, on the other hand, requires the following:
1. Understanding the board state and necessary objectives. Ex: I'm France. Germany is strong, so I need to ally with England.
2. Communicating, in human language, with other bots to try to achieve those objectives. Ex: "Hey England. Germany is getting too strong. Want to ally?"
3. Relating messages received to current board state. Ex: France wants to ally against Germany. I've got a plan to attack France, but Germany will likely profit more than I can.
4. Giving an intelligent response for the scenario. Again, this sounds simple enough, but there are so, so many subtle factors to take into account. Do you trust Germany? Who's the better player? What level of honesty is best? Lying is a strong strategy for a stab, but telling the honest truth will build rapport and may ultimately save you.
5. Do this for any given variant, with little to no textual data about the normal messages sent.
6. Ideally, outperform humans in this. I'm quite confident AI will eventually beat humans in gunboat quite easily. But combining that with the diplomatic element is much harder than it would seem at first glance. A map with fewer players would help, but it doesn't solve the fundamental problems.
Anyway, that's my "expert" opinion on the topic. Relevant xkcd:
https://xkcd.com/1425/