When you use colours in your design system (or style guide), it is important to take into account the impact of designating a colour for a specific purpose as it will most definitely have flow on effects. Not only will you create an association for the user when the same colour is used in other contexts, it will also impact on the meaning of other colours used for related purposes.
So the issue is not whether the colour can be used or not, but if the use of this colour then has impact on the rest of the visual language of the user interface.
From the question it is hard to determine whether the issue comes from personal preferences or subject views about the meaning of the colours, but in any case you should do a careful analysis of how it will impact the existing design and if it is going to impact any future changes you make to the alert and notification design patterns and components.