If you've used the (preview at this writing) PowerBI Audit Log in the Security and Compliance Audit Log Office 365 Admin query tool; you'll notice that it does not have a column for: "result" or "exit code" or "success/fail/permission-denied".
A very problematic issue has resulted for me.
Example:
Let's say you build a report/dashboard off a SQL Tabular source (connected via gateway of course). And you apply security using SQL Tabular Roles (at the Tabular level, not the PowerBI level). Then, you share the report/dashboard to a PowerBI Workspace with several users. Fine so far...
Now, let's say Suzy Smith does NOT have Tabular read-rights. She can't use the cube from Excel AND she can't view content shared w/ her from PowerBI. Great. That's how it should work. The dashboard would render the (X) "ERROR" message for her on each object - as appropriate.
BUT - and here's the caution for enterprises - If someone shares a dashboard/report w/ Suzy Smith and she's clicks it (she'll get the appropriate error on the report) but the audit log will create an entry that reads: "Suzy Smith - ViewDashboard - datetime".
Thus, the audit log notes that Suzy Smith did see the dashboard. In reality, she didn't. She got the (X) error on every object on the dashobard. Suzy Smith did NOT see the company's forecast for next quarter. But your audit log implies that she did.
Your company's auditor ~may~ not like this.