Civ 7 should privately, quietly and slowly ( months not years ) abandoned . Key resources and any competent staff sent to other projects say Civ 8 Or other PC ventures.
This version of "Civ" should only have additional resources spent and retain in area's that perhaps have the most chance of growth - perhaps casual , console players with an increased Meta/Leveling up process.
Maybe more toons, cosmetic costume's , multiplayer events, leader boards, tournaments
They should build a small professional team of modder types who introduce experimental beta features that come and go like live service seasons, from scenarios to bonkers rules changes. This will entice a small community who keeps up with these changes and be a low-cost source of buzz. Then, once some set of a half dozen of these experimental changes becomes popular with the "I wish they'd bring XYZ mode back" thing, then release a polished set of those experimental features as an expansion and see if it sells. This necessarily means releasing mod tools. You would have mods incorporated into a pack for an experimental weekend so all players are on the same page.
To fund this, they should release new civs one civ at a time for like $8 a pop. These should primarily be art assets that modders can then incorporate through mod tools into different things. They could
literally do a Middle Earth civ like Gondor just as a kind of gag, but then that introduces fantasy models into the building assets.
There's a version of "give up on Civ 7" where they don't completely give up on it, just take it so unseriously, that they'll give a chance to the community to do stuff with it. Like I said, there's always that warhammer model of the community owns the game now, but as the official developer you can sell assets to people and they'll pay. Just a small team of "event curators" to hold experimental weekends etc.
Meanwhile, the main staff straight to Civ 8 with 5 years from now release. Make Civ 4 but with army commanders, navigable rivers, canals, floods (and flood control/dams) as vanilla features. Like, literally Civ 4 with commanders and hexes and 1UPT. You could easily embellish Civ 4. For one, you could make villas specialize. Not as districts where you can only build certain buildings, but you can "flavor" your villas to support both tall (a do-it-all city with multiple villas with diff specializations) and wide (many cities which focus on one specialization at a time). Civ 4's government system was cool, but you could cross that with a very light version of Civ 6's civic system where government type has different slots for different bonus policies.
Etc.
(You know Army Commanders could be designed to function as Civ 4 doomstacks, but are vastly more effective when laid out one unit per tile. So if you have a stack of units, all by the primary unit are "auxiliary forces" with substantial combat nerfs. A hybrid 1UPT and doomstacks is totally possible.)