I think if AC:EMPIRE adopted this formula it would be about "smaller open worlds" wherein Egypt is just their version of "The Showstopper" (but probably with more missions and a mini-plot arc. Then later, if they had a Pirate-Themed sandbox it would just be an island settlement (like Havana) with another mini-plot arc and a new Assassin character (so by then you'd have 2 selectable Assassins). There's these towers to sync with.... then missions set in this map. Unlockables galore matching this era/style.
Then if you switch Maps you just get another sandbox in another place (Paris during French Revolution, a city in Spain during the Inquisition) - and you get towers to sync with and missions, unlockables. Each time you buy an "episode" it's a new Era, New Map, New Assassin, New Mini-Story, New Unlockables.
It's kind of like if you imagine going to Sapienza and in one "visit" you can do "World of Tomorrow" and "Landslide" and "The Icon" by going to different Mission Start markers on the map and activating it (which is the current style in AC).
Then from the Menu you jump into another Sandbox, say Marrakesh, and you can do "A House Built on Sand" and "A Gilded Cage", etc. So it's like a "mini-open world game collection".
And yes, I am half-expecting that if they do this they will re-hash Pirate era Havana and the French Revolution. How else are they going to "greatly improve visibility for hitting targets"? It will happen because they will use everything that's worked before and simply turn them into a massive library.
On one hand, it'll be "the biggest Assassin's Creed game ever conceived". On the other it will also be "The biggest bang Ubisoft has gotten for its buck because rehashed assets here we come!"
They might even try seamless multiplayer, kind of like what was promised in No Man's Sky where if you are both in Havana and you accept an invite you can see each other in Havana and do coop stuff.
They might even allow you to break continuity such that you can choose any Assassin you've bought/unlocked and use them in any Map/Era you've unlocked. So you can have your Pirate Buccaneer running around Ancient Egypt. And if you say: "No! That's illogical!" .... So was IOI allowing us to roam around Hokkaido in a Santa suit, or visiting Marrakesh wearing a Yukata - something I'm sure an AC "Episodic" team would have pointed out in their pitch.
They will no doubt add: "IOI got into trouble because they had yet to make everything for future episodes! We don't have that problem! We have Terrabytes upon Terrabytes of OLD Assassin's Creed locations going all the way back to Jerusalem! We just update them!"
"After we've sold them Ancient Egypt we'll make sure the next episode features Ezio Auditore and uses updated versions of AC2 locations! They will go ga-ga for Ezio and buy it all up! Then after that we feature Edward Kenway in the next episode and claim that this mini-story happened after Black Flag....."
They'll say: "It's an AC game with no limit to value but at really low cost!"
P.S.: The punchline is that one of those Cost Savings means all the guards and basic NPC's speak American English! So they just do all guard and crowd voiceover work once and then reuse it forever!