If ARQ is turned Off then no you would not need to exclude your sitemap file. You should already have an exclude rule created for your sitemap file. If you don’t then run the Setup Wizard and the rule or rules will be automatically created.
Keep in mind though that the Setup Wizard will turn AutoRestore (ARQ) back On after it has created all exclude rules and backed up your files for you. You can turn AutoRestore Off again of course.
The Setup Wizard checks for existing sitemap.xml and sitemap.xml.gz sitemap files and automatically creates these AutoRestore file exclude rules for sitemap files if they have not already been previously excluded from being checked by AutoRestore/Quarantine.
BPS Pro 6.5 Whats New (this information can also be found in BPS Pro on the Whats New Menu page)
http://www.ait-pro.com/aitpro-blog/4845/bulletproof-security-pro/whats-new-in-bulletproof-security-pro-6-5/
Setup Wizard Read Me First
http://forum.ait-pro.com/forums/topic/pre-installation-wizard-and-setup-wizard-read-me-first/