That’s an interesting piece of lore, but it’s not part of the established canon of Avatar: The Last Airbender.
In the series, very little is revealed about Piandao’s parents or childhood. We know that he was a renowned Fire Nation swordmaster, a member of the White Lotus, and one of the greatest nonbender warriors in the world. However, the show, comics, and most official reference materials do not state that:
•He was born to noble firebending parents.
•His parents abandoned him because he was not a firebender.
•He grew up in an orphanage.
Those details appear to come from fan-created stories, roleplaying material, or unofficial lore rather than official Avatar canon.
What is canon is that Piandao became a legendary master despite not being a bender, which fits one of the franchise’s recurring themes: skill, discipline, and character can be just as important as bending ability. His training of Sokka is one of the clearest examples of that idea in the series.
Fun Facts: Master Piandao was born to two firebenders of noble heritage.
Ashamed that their only don wasn't a firebender they say him as a disgrace and left him at an orphanage.
He later became the greatest sword master in the history of the Firenation.