I've been experiencing this phenomena in which my swatches would disappear every now and then. One day, I'll have all the default swatches available in the swatch menu, other days, it'll only be the color white.
Please get in touch with us at any of the other support channels – https://helpx.adobe.com/support.html . Since this is not a generic issue that we can reproduce at our end, we will need someone to look into your machine to figure out what is going on here.
Ashutosh Chaturvedi | Sr. Quality Engineering Manager – Illustrator
Thanks for reporting the issue. Is this issue very frequent? As I am unable to reproduce this on my end. Can you please send the detail steps.