Due to trade mark problems they have to protect them self from being sued...........
If you remember well when you started using your tool for first time they make you agree to there terms and conditions therefore if you change the icons and if any trading stander guy see you using the tool with trade mark icons you will be the responsible and not Autel, hence the reason they don't let you change the icons in this new updates software.
To me icons is not a problems as long as the software is bang on and doing its job I am happy........