Kind of surprised you haven't gotten more responses. I guess ppl just aren't paying much attention to the MoO forum here at GoG. You might try posting your question over at VideogameGeek here, as that site generally has more dedicated "old-timers" who contribute to the forums.

Link you had posted make even this forum looks good tbh.
upd. No, make "even this one looks VERY good", sorry. Words "dedicated oldtimers" used for given link start to sound oxymoron tbh.

Recently, I came across this in a discussion about another game: The classics, in my opinion, took a concept and turned it into a game. Here are some old games that I can think of:

Pirates! The concept is the Caribbean Sea is a giant sandbox and you can sail your ship where you like. There is also a bit of tracking down enemies and searching for treasure. The concept is you get to be a pirate!

Starflight: Similarly, a piece of the galaxy is a sandbox and you can fly wherever you like. Read some of the reviews for this game. If you played this game in childhood, then this game brings your childhood back to life. One of those reviews, somebody was talking about building a starship out of chairs and blankets and playing the game pretending he was actually in the spacecraft.

Civilization: Here the concept is to build the greatest nation and take over the world. It very much had a one more turn addictiveness. You get to be a ruler!

Master of Orion: Now the same concept is applied to the galaxy. Build the greatest empire and take over the galaxy. For added flavor, they have several races, and one special planet. Since contact only occurs when planets are in short range of each other, it is possible for opposing ships to encounter each other before first contact. This gives the feeling of exploring the unknown.

So the general concept is if the game engages the player in such a way that the player feels like a part of the story.

Master of Orion does this. I actually try to avoid looking at the map to avoid finding out who the opponents are, just to get the feeling of exploring unknown space.

Here is something I do not like: Truncation errors. I hate losing BC's and gold coins to truncation when distributing resources. How about a clever system of ensuring all the resources produced get distributed?

Well, in moo2 you GET stuff due to truncation instead. Clever enough, or there is still alotta for further improvement? I mean - its REALLY the most critical problem you had get with whole game?

Yes, it's about core fantasy, I get that. In fact my question is about core fantasy too.
Do you consider the MoO experience connected with some other experience? Like from the movie or book?

You want to know how to make a game like MoO and being successfull? Easy! Just make a huge universe, include a mass of different races and the ability to make your own race, give the player a very huge tech tree with usefull techs, let him build his self-designed spaceships, write some informative and a little bit humourfull text for the techs, give the possibility to choose from a few fair difficult levels and, last but not least, MAKE IT BUGFREE!
Oh, I forgot to mention: Sell it for a fair price!
That`s all you have to do and you`ve got my money in the pocket.