This is useful in case the BIOS flash fails and bricks the motherboard.
I can easily remove the BIOS chip with a pair of tweezers and replace it with a new one.
If AMD implemented an easily removeable and replaceble BIOS Chip in plastic IC Socket standard on all of their motherboards, then if significant increase in BIOS memory were needed in future, it should be possible to upgrade the BIOS Chip.
Since Motherboard Manufacturers need to make money for their efforts, perhaps they should give you a choice to:
Pay for a new BIOS flash with limited UI and feature set due to BIOS Chip limitations which will allow you to use new CPU with existing BIOS chip if that is possible.
Pay for a new BIOS Chip which would allow you to run your older board with a newer generation AMD CPU. All you would have to do would be upgrade the BIOS Chip.
Upgrade your motherboard to a newer motherboard chipset and features which supports new AMD CPU.
Does that sound like a better solution moving forward?