Why are manufacturers so reluctant to change model numbers when they add features?

[StephenG1CMZ]

I have two examples in mind.

The old Prime G1 calculators originally had a keyboard that received criticism regarding its legibility.
The keyboard was improved but for a while it was not obvious which keyboard you would get if you ordered one. The likely consequences being some consumers either delaying purchase or being unhappy with what they got. The new G2 has the improved keyboard and other improvements.

Another example is the Casio Cg50, which has been advertised in my local Whsmith as being a graphic calculator with Python. Whilst that is somewhat inaccurate (it's micropython, and it doesn't do graphing).

But the advertising (at the Point of sale in-store) has changed, and no longer mentions Python, but the model number remains Cg50.

An unwary buyer remembering last weeks advert might buy the old CG50 without Python (if they can actually buy one - it is never in stock, whether its the one with Python or the one without).

Surely the addition or omission of Python in a product should be made clearer to the end-user?

Not all of whom are as likely to study the packaging before purchase as readers of this forum would.

Myself, I am left wondering... Does the change mean someone complained its not Python but the product is unchanged? Are they selling old stock without Python? Or has Python been removed from the Cg50 because of a problem?
It would be so much clearer if the Python version had its own model number, instead of having to guess what the calculator can do.