At this point I'm thinking a manufactured good would be more likely (for some group known for making a certain thing, like purple dyes and Phoenicia (except Phoenicia has almost no chance of getting in in my opinion, that was more an example)
This would be a perfect example of one that actually
would fit. If they announced that the new resource was murex, then that would be a pretty good giveaway that the Phoenicians were in. The connection there is actually inevitable, unlike all this "rubber would have to mean Kongo" or "glass would have to mean Venice" nonsense.
And actually, I'm not so sure the Phoenicians are quite as unlikely as all that. I now think they may be a potential candidate at least, for three reasons.
1. With the new Trade Route system, they'll want civs that are known for trade so they can work in the Trade Routes to their UA. The Phoenicians are known for very little else. A UA involving extra Trade Routes, say, would be perfect for them.
2. As far as resource/civ connections where the resource would have to mean the civ was in, murex/Phoenicia would actually be a very strong one. In my opinion, it's the strongest suggested here so far. (Buffalo/Sioux and seals/Inuit are the only other contenders I've seen that I think would fit.)
3. We've seen, with the news about France that came today, that they are willing to completely overhaul the UA of an existing civ. So it could be that Dido's "Phoenician Heritage" is out--or at least trimmed down to the mountain-crossing thing and renamed. Maybe the free Harbors would go to Phoenicia instead. Maybe not. At any rate, the fact that the Carthaginian UA is currently called "Phoenician Heritage" no longer counts as evidence that Phoenicia itself is out.
None of this means, by the way, that I think it
is Phoenicia. I'm not going to clamp on to Phoenicia like a mad dog and insist, in the face of all counter-arguments, that NO REALLY GUYS IT IS PHOENICIA. I only say it would fit with what we've been told so far, when very few of the other suggestions I've seen do. As happy as I would be if it were Phoenicia, I wouldn't be at all surprised if they're not in and it's someone else entirely.