The first era "Neolithic" looks like a very good idea: this is a good way of creating randomized starting positions for the various cultures: there can be search for bountiful territory and competition for it. Tribes that cant keep up or are less lucky can start in a disadvantage which should make the start game much more interesting due to its randomness that the player can still gear

Its also very useful for getting all the factions reach a higher amount of cities early in the game if they choose to do so instead of the slow progression in CIV games and EL with settlers only

Suggest to allow creation of neolithic settlements as an option next to foraging hunting and exploring so that there are further alternatives the tribes can choose from. These should not be real settlements just provide some bonuses to units around them (heal, vision, more food collected)

The whole idea of nomadic faction would also be great to keep later on: there could be an option to choose nomadic cultures if the culture was nomadic up to that point (all tribes start nomadic). This does not mean they don't need to be able to build settlements, just that their settlements are mobile (like the nomadic faction in EL)

Regarding era progression: It isn't clear to me from the vids if all factions progress together or if each faction has its own progression through the eras. I really hope its the latter as it would further diversify the map state with various factions having different era progression status.

The concept of rubber bending all the factions up to the most advanced factions is less realistic, fun and undermines the players drive to progress.

Having segregated progression also leads to some very thematic situations where advanced empires can bully "barbarian" factions around them that are simply less advances as well as naturally lead into a colonization era where the first factions to reach industrialization can start extorting other less advanced factions. This is fun for the advanced faction as they get a huge boost in economics and fun for the others as they can combat the colonizing factions in a minigame of keeping their independence or breaking off from their overlords

There should ideally be only one instance where other factions can get a leg up in era progression and that is during the industrial revolution if they are colonized by an advanced faction. The tech at that era was a game changer and should give huge advantage to the agressor (the difference between an industrial faction and a late medieval faction should be much higher then an early medieval and late ancient faction) leading to large amount of colonizations

This should also be the time when neutral tribes and factions should disappear and get melted into larger empires via colonization preventing them from still being around in modern times

When a faction is colonized they should automatically loose x percent of their resource production (all type of resources: money, raw materials, luxury goods...) to the controlling nation BUT also get a massive reduction to all tech up until industrial revolution. This should result in these colonized factions being able to catch up and eventually revolt and brake free again

Factions that are behind their era progression could still try to hold on to their independence and this should result in exciting fights for both sides mirroring history

If this is the only catch-up mechanic factions have era progression wise that would be perfect and right around mid-game as well basically ensuring that there will not be any factions left with pre-industrial tech in modern age: they are either:
A: Colonized and thus progress faster to catch up (but not instantly like in CIV games which is very annoying) eventually breaking free
B: Manage to fight their way through which will only really be possible if they manage to catch up technologically on their own (Japan model)