Has the Remote Dashboard Refresh always been 5 minutes, not sure if I understand the meaning of this limit?
I can refresh the remote Dashboard via cloud link I thought. Or is this going to be a change coming up?
Not always, but for a bit now, yes. This means that if you just leave the dashboard sit there, you'll get a note on top that it's stopped refreshing due to inactivity, and it will offer you a button to refresh now (that way, it's not sending events over to the cloud to something you're probably not actually using). If you haven't seen this pop up in cloud dashboard links, the "Devices" or "Dashboard" tabs in the mobile app, and similar uses (again, it's not new with this particular change), you're good! And even if you do see it once in a while, it's an easy fix/workaround even if you don't want Cloud Extend.
EDITING TO ADD: Local dashboards, of course, are also not affected.