This is one of the most popular myths in 3rd Strike. The game has been out for 9 years, and people still think Chun Li's low forward is a link. It's not. It's a cancel.
Everyone thinks it's a link for a thing same reason; when you see it combo into super, it looks like a link. But it's not a link. Chun Lli's low forward has the property that you can cancel it very late. The move has already gone into its retraction animation when you cancel it. This is what people are seeing. It looks like the move ended and then Houyokusen started. But it is just being canceled really late into the move.
That's it. It's just a very late cancel.