To avoid wasting time finding bugs that are not related to performance, it is important to have a stable application that has been thoroughly tested.
If load tests are made just before the production deployment, there will be little time left for our tests. This means that if the application has not been functionally and technically tested (unit, integration, etc.), every bug detected during the load tests will jeopardize the start of production at the planned date and under good conditions.
Load testing (even if it can be automated with CI) is not here to replace Non Regression testing.
Source: “Master Apache JMeter From load testing to DevOps”, Antonio Gomes Rodrigues, Philippe Mouawad and Milamber, https://leanpub.com/master-jmeter-from-load-test-to-devops