We saw it with both Moriah and Sugar. After their defeat both the Shadows that Moriah stole and used went back to their original owners. and the people who became toys by Sugar were turned back to normal. So why didn't the same thing happen with the Homies after Big Mom fell into the lava?
The abilities work differently
Sugar and Moriah transformed one thing onto another akin to a curse Sugar getting knocked out broke the curse and turned them back to normal
Big moms ability works differently she didn't transform one thing into another thing she took a living soul and put it into something to bring it to life
That portion of soul is now separate from its original body and is technically a completely new entity with its own perspective and memories has far has we know non of the homies have memories of when the soul that powers them was in someone else
Think of it like this
If your grandparents die would all their children and grandchildren just disappear?