If you are talking about in the 'System Requirements' section of the website, I have found it outdated.
Isn't CentOS considered a supported operating system?? Yet, it is not in the list. Neither are 1 or 2 others I'm sure.
However, to answer the original poster's question, I do not believe SuSE has yet been supported by DirectAdmin. If it has, I haven't heard or read about it. It supports mainly RedHat, CentOS, FreeBSD, and Debian as far as I know. But, I'm no expert on the subject.
Louie