I think there's a gap between running tests without "defined starting and ending states" and chaos engineering. This would be closer to exploratory testing for

I think there's a gap between running tests without "defined starting and ending states" and chaos engineering. This would be closer to exploratory testing for me, however rather than having a QA team run them you're outsourcing to the users at the expense of risk. Everyone does this (it's called a release) and you can deal with this in two ways - have tracing and monitoring in place to collect the logs from your unpaid testers or ignore it. Add techniques like blue green or canary deployments and you somewhat reduce the risk cost. However this cannot be a replacement for decent prior software testing practices.