en.wikipedia.org/wiki/Nahui_Ollin

Multiple authoritative sources place Nahui Ollin in the wider Postclassic Mexica world, not just the 1500s.

• LACMA describes an "Ollin Relief, 1250–1521" and states that "At its center is the glyph Nahui Ollin (Four Movement), the name of the solar era". That date range begins centuries before the 16th century.
• Princeton University Art Museum describes a Mexica Postclassic Period, 1300–1521 sacrificial stone whose central signs "refer both to a specific and important day called Nahui Ollin ... and to the name of the current age more generally." Again, that evidence places the concept in the broader Postclassic era rather than making it a specifically 16th-century concept.
• INAH likewise describes a monolito de Nahui Ollín as a Mexica calendrical symbol in its Tepeapulco museum, treating it as part of the pre-Hispanic Mexica religious/calendar tradition.

Because reliable institutions describe Nahui Ollin as a pre-Hispanic Mexica/Nahua concept and glyph attested across the Postclassic period (roughly 1200/1250–1521), calling it simply a "16th-century concept" is inaccurate and misleading.