Based on both BfA and SL feedback vs. what ended up going live, I’m not sure waiting that long to post the idea would give them enough time to consider it. Even early alpha feedback seems too late for a lot of things. It was only Spriests that really managed to get a major change out of their feedback.
I don’t think technically it would be that hard to swap an existing talent out for a slightly modified Sheilun since it already exists and isn’t something that would have to be created from scratch. Personally I think even though pre-patch is tomorrow, it’s not too late for mechanical tweaks before SL official release.
I feel like this was only ever interesting as a cheap chi generator. Even if it becomes numerically worth pressing, it won’t really be an unpruned Expel Harm. Without Chi as a system it’s basically a new spell using the same name. If it was meant to be about bringing back something old they’ll have to look elsewhere.