Well, yes, what you said is generally how the books have phrased it. There's really nothing much to imply that this ritual ever existed, it's only my own personal thought on the matter.
My point was just that it's a very odd thing to be on somebody's mind, unless it's a thing that really happened at some point. It's a little like, I dunno, how the word "Thursday" originally came from "Thor's day," which wouldn't fully make sense unless Thor had, at one point in human history, been a much more important figure than he is today. I'm trying to think of other examples, but I'm not familiar with the meanings behind most English words, so it's hard to explain what I'm talking about.
It's really more about the ways words evolve, than what they mean today. Words don't generally come about because people were thinking "hey, wouldn't it be interesting if," but rather "this is what is." Words have to have an agreed-upon meaning that is widely known to everyone, and hypothetical situations don't generally fit the bill. If you can find me an English counterexample to this, a word that is based only on a hypothetical situation and not something that ever really happened, let me know.
In any case, the more I think about it, the more I think that this ritual, if it existed, has almost certainly faded away from Andalite history over time. With the various shorms that we see, the ritual probably would have come up at some point in the series if it was still practiced. No, I think it's probably long gone, leaving the word shorm as its only legacy.