Can dashboards be scrollable?
Provided the dashboard is being viewed on a device that can scroll (as opposed to say a kiosk without a UI) yes, scrolling is fine if you need it.
Is scrolling good UX?
With the average end user spending 69% of their media time on smartphones, attention to mobile UX features is a top priority. Scrolling is a vital part of this user experience, and it's one that's frequently underrated. Scrolling is how people will find your content.
Should a dashboard scroll?
Not necessarily — As long as you do it right. It is always better to allow scrolling than to have an overloaded dashboard without it. Scrolling is an action that most users are familiar with (think about Facebook or Instagram for instance — scrolling is in their interface core).