Finding the Capitals

Because the structure sets are unchanged, everything you already use to find settlements still applies:

• /locate structure minecraft:village_plains (and village_desert, village_savanna, village_snowy, village_taiga)
• /locate structure minecraft:pillager_outpost and minecraft:swamp_hut
• Explorer maps and wandering-trader directions point at them normally.

Settlements only appear in chunks generated after the content is installed. Adding it to an existing world is safe, but already-explored villages stay as they were -- travel outward to find the rebuilt ones.