On the plus side, this introduces a tiny opportunity for post ww2 peaceful German civ... for the fourth age? I mean, I can't imagine devs making fourth age work like the first three ages in terms of demanding civ change and having equal roster to them (neither I can imagine having as long tech tree as other three), it would be also very painful having to decide whether to put say America in the 3rd or 4th age :crazyeyes: but on the other hand there seems to be a clear conscious push to avoid referencing post ww2 world (or post 60s world?).
It is very interesting how 3rd era civs are named as not-modern-country-in-general-but-specific-pre-ww2-regime. It really looks for me as if civs such as Soviets, (postcolonial) India, (post ww2) Germany, (CCP) China, (post ww2) Japan, Thailand (renamed as such in the 30s), (postcolonial) Indonesia, modern Etiopia etc were purposefuly avoided in the 3rd era to use them in the 4th. I mean why else would devs use their pre-ww2/ww1 predecessor state in every instance possible.
Personally I see three options:
1) Fourth age is going to be special in some ways, for example allowing ascending to it with the civ from the 3rd age or reforming it to a "newer version"
2) Devs actually are going to make yet anothet crazy bold move and indeed introduce 4th era with the entire separate civ roster - so no America post ww2

3) Fourth age is indeed going to have an entire separate civ roster, but some countries such as America are going to get anyway as their sci fi futuristic versions