Question about cultural armor timeline/relevance on green

[soronil]

Excited for Green, and I also really like the cultural armor concept, so just had some questions as I try to plan my alts way too far into the future
Are all cultural armor recipes (that exist in our timeline, and in blue today) introduced at the same time? Or at different times? I am mostly interested in:
Clockwork Watchman Armor (Gnome)
Imbued Steelsilk Armor (Erudite)
Enchanted/Imbued Koada'dal (High Elf)

These weren't released until Velious, right? At Velious, or how long after?

Also, how long can one expect for these armors to be useful vs Velious content? (I know some races are much better than others)