My Cold Steel Khukri came with a short history of the knife, nowhere near as detailed as your explanation but basically said the same thing.
It was believed that style of knife was brought to the area by soldiers in Alexander The Great’s army. This would have been roughly 330 BC.
I wasn’t aware of that.
AFAIK, Alexander’s campaign didn’t go much beyond the clash with Porus, which cost Alexander heavily, and forced him to quit pressing on into India proper (some say that the soldiers feared battle with the significantly larger, better trained Magadha army in northern India - especially considering the fact that Porus himself was merely a border tribal chieftan, while Magadha was an established empire). Nepal would be located far, far to the east of where Alexander encountered Porus - a separation of perhaps 1000 miles, or more.