We do know that the basic ride system is not being replaced, and the shed remains to be open again at some point next year.
I know you are being pedantic, but such simple, basic facts remain.
No Mystic Meg, no "hopeful expectation" just common sense and obvious logic, something sadly lacking in this topic in recent months.
It depends what you define as ‘new attraction’ doesn’t it?
If your definition of that means that it needs to be a new ride system, then no, it almost certainly isn’t going to be a new ride.
Personally, particularly with dark rides, I consider the hardware to be a relatively insignificant part of it. In Fantasy Land at Disney there are numerous dark rides with very similar ride hardware, the difference is the experience within the building which is dependent on the theming etc.
If it is the intention to keep the majority of the theming, but remove the older stuff, get some newer bits in and keep the experience largely the same, then yes, I’d agree with you. But everything we’ve heard, including an interview with Wardley recently, suggests that it is going to be more comprehensive than that.
It’s purely down to opinion, but personally if we get the vast majority of the interior gutted and replaced then I would consider that a new attraction, albeit one with the same ride system and genre as the previous one (but probably a revised theme as, again, Wardley has mentioned it will have new back story).