No, it is soldered to the storage module. You have to desolder the flash chips from that module and replace them. You can't just order a bigger storage module from Apple (or anyone else) and plug it in.
Again I have no proof, but there must be reasons he claims they have to be blank NANDs
If you are building new SSDs, it makes sense to be certain that used NAND chips aren't slipping into your supply chain.
They do have a limited number of write cycles that they are good for, after all.