Comment by gruez

That's why the examples I listed are plausible reasons for changing the model number. For firmware, it's plausible that it warrants changing the model number because firmware can and do affect performance, as other comments has mentioned.

Also I really don't see this being something that judges will stop. You see other CYA behavior that has persisted for decades, eg. drug side effects (every possible symptom under the sun), or prop 65 warnings.