Hi, it's a good idea to sync the category of outlook in dynamics 365, it's important because the customer need to track a category color also with dynamics 365.
I see that now it's not supported: https://docs.microsoft.com/en-us/power-platform/admin/use-outlook-category-track-appointments-emails#category-based-tracking-with-dynamics-365-for-outlook

i hope you implement this functionality
thanks.