Since they do tend to leave cut content in the files like cards they made that didn’t make it to the live version, that they went out of their way to remove those flags in the PUP means we probably were not supposed to know they exist yet.
I can confirm that at least Poland is (or was) being worked on as a revolt. I was checking out the new skins and lo and behold the new Dutch lancer is based off a Polish revolution unit.
<churchwaardgelders>
<assetreference type="GrannyModel">
<file>units\revolution\polish_lancer\polish_lancer_rider</file>
<materialvariant index="2"></materialvariant>
</assetreference>
</churchwaardgelders>
While they may still be under development as full civilizations (and that could explain why they yoinked them out of the files after we saw them), they likely are being worked on as revolutions at the least, which leads to the question of where would they fit in as revolts (or maybe a revolt-like mechanic)?