Undoubtdly Miyagi Sensei studied Niafanchi and other kata. To my best knowledge it was never part of the Goju kata he taught. On the other hand his friend Mabuni trained under both Hiagonna and Itosu, did include it in his Shito Ryu (really covering the full range of Okinawan experience).
So some who teach Goju may have made smiliar journeys and added it to their teaching, but IMO it's non-standard as a Goju tradition.
But as for movements, most movements can be found in most systems, depending on how you define movements.
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