A possible side effect of Exordium, is the population of Amarr (and here I mean Amarr space) “may” decline, even if only slightly.
Before Exordium, all 3 Amarr career agents systems were 4 jumps from the Amarr system, the trade hub. Now, they are either 26 jumps away if they take the “new” high-sec route (the “shortcut” introduced with the gates between Rayeret and Jakri), or 11 jumps if they use the shipcaster (do they need to enlist to use it, like the other shipcasters?).
What I mean is, before, Amarr had a chance to retain NEW players being born there (I’m not talking about veteran’s alts who are moved to Jita, Null, or wherever outside their race empire because of whatever reason they create them). Some NEW players could be: hey, I’m here alreay, what can I do around here, and “settle” in an Amarrian system (even if only for some time, when they figure it out), for mission running, mining, abyssal, whatever. The Amarr hub is active, so buying and selling stuff is fine. If you had no specific goal at the beginning, and were just experimenting the game, settling in the same space your first character is born is an easy “by default”. Exordium is definitely “it” now.
Now, Amarr will need to be attractive to get them to move there, since it cannot just capture them by default. If Amarr pilots going out of Exordium through Yulai wanting to do some PVE stuff, Dodixie is right around the corner (4 jumps from Manifest, 7 total from the career agents). That’s the closest hub to sell their Exordium loot, and to buy their first fits. Why take the long route to Amarr just to do the same type of activities you can do next door from Manifest?
Jita is still attractive and I guess video guides and Newbro channel probably still recommend it as the most active hub, so the change with Exordium is insignificant.
Rens “might” lose some new players to Hek, as Hek is now the closest of the 2 from Exordium (both through Yulai or the shipcaster). Not as far as Amarr, the Minmatar space may also lose a bit to Dodixie/Gallente space. Rens used to be the closest to Malukker and Embod, and Hadaugago was only 2 jumps from Hek, but in a different economic region so, if you don’t know much and just look your regional market, Rens was probably the default hub to sell your career agents loot. (Same logic applies to Embod, of course, though Rens was a shorter distance, new players probably took the (slightly) longer route to Hek as it was the obvious trade hub when they look at the regional market from sitting in Embod).
Time will tell if Amarr space (and the trade hub) will be biggest loser with Exordium.