You will be losing any comments and special code formattings like indentation and extra spacing if not stored in a separate place (without any memory saving). These are highly valuable in assembly code
The fact that code that has been generated from macros will not be visible. You will be losing that information if not stored elsewhere (again, no saving of memory)
You'd be losing all information on assembly pseudo-instructions (ORG, OFFSET, DC.B, the like).
You'd also be losing track of what's code and what's data, which is a significant problem when your disassembler would need to figure out whether 0C9H should be
RET
orDC.B 201
(a Z80 example). Modern disassemblers try to follow code streams to decide whether areas are code or data, but that's way beyond the capabilities of an 8-bit micro (and still not 100% accurate when jump tables are involved).It's a huge difference whether a table was originally created as bytes, words or longwords, and then whether it was created as absolute or relative values (*-label or label). All of that is lost in a disassembly.