Why on earth would someone do something like that? It must be a manufacturing fault IMO, because purpously removing the possibility for the customers to upgrade their flash memory doesn't make sense in any way.
I don't know enough about flashable memory, but couldn't this be a "feature not a bug" type thing, so that people can't completely screw up the flash ROM and have to return it? Admittedly as I've been using PCs for years in the context of BIOS flashing, it does seem an odd thing to do. Perhaps it's a workaround of an issue with the flash ROMs being used, to avoid one problem with them they're locking them?
Nonetheless, I concur with someone else's advice to ask on the appropriate support forum. The A1 dev list? The amigaone yahoo group?