I don't think that this theory is very plausible, mostly because there is a simpler explanation. It is more likely that Odium caused the chasm when he caused the deaths of Sel's Shardholders for a number of reasons. One is simple pragmatic story telling; having a character that we're suppose to root for be the cause of countless deaths, even unwittingly, would be difficult to pull off well. However, it is exactly the sort of thing that would be done by a villain (like Odium) do demonstrate how evil he is. Also, the connection that lyht noted between the chasm and the shattered plains also seem to point towards Odium. The shattered plains are the remains of a city destroyed in a Desolation, which are presumably caused by Odium.
Also, we know that highstorms have some kind of connection to the Stormfather. I don't know if the Stormfather can Worldhop, or how far away a highstorm can stray from the stormfather before it is no longer a highstorm. It's possible that even if a highstorm was somehow sent to Sel, it would die out without the power of the Stormfather backing it up.
