That’s a common practice in enterprise software licensing agreements. The organisation that is being audited signed up for this. Oracle uses audits to enforce being correctly remunerated under the agreed metrics. Nothing scandalous about it. Not sure if audits only happen for on-premise deployments and SaaS usage is automatically metered.
Never heard of it beside Oracle. Everybody seems to hate them.
My company had a Microsoft audit a few years back. Had to turn over a MacBook to some guy who tried to launch Word to find illegal Office licenses...
Audits common place? Maybe. But name 3 software companies which audit as aggressively as Oracle.