The only way to know that no *iota* of that boxed Elric product ever exists again is to wait and not see.
The only way to ever know anything for sure is to see it with your own eyes. So, you're set up for failure here because the answer is basically 'until the day I literally die, it's always possible this tooling will be used again by someone.' It's an impossible standard to argue against beyond just saying 'okay, sure.'
But, we have the owner of Harvinger saying 'we can't and won't use that tooling for any other figures, it is exclusive to Elric.' So, I'm going to believe him until he proves to be a liar about how the company approaches licensing and tooling. The ONLY other option is to say 'he lied.' So either you think Rob is a liar, or you don't.
But we have seen the executed evidence on toy shelves where there's been lots of reuse between licensed and in-house brands
We haven't.
My specific point was that Mattel could use tooling -they owned, because they owned the IP it was created for- for a different line, but that they were never able to cross-pollinate tooling from brands they -work on- either for their own in-house IP OR for other brands they were also working on.
Hasbro, too. There is zero re-use between G.I. Joe, Marvel Legends, and Star Wars Black Series even when it would make all the sense in the world to borrow this or that part into the other.
Even HACKS, if I remember correctly, had the same issue. They could use existing HACKS tooling to make Hero HACKS licensed characters, but tooling made FOR the Hero HACKS figures could not be transposed back over to regular HACKS and had to remain with the characters the tooling was created for (i.e. the HACKS nude body could be used for Tarzan, but Tarzan's head couldn't appear later on with a HACKS fantasy figure).
-My- point was simply that, to my knowledge, we have never seen what you're suggesting in the last 20-25 years, where tooling from branded IP not owned by the company that made the tooling is used anywhere else (short of it being stolen). The only time I can even think of when that ever happened was when the Ewok Village was re-branded as Sherwood Forest for the Robin Hood line. That's a DEEP cut from a long time ago.