In OpenSearch 2.4, we are introducing a new feature: Multiple Authentication Options for OpenSearch Dashboards. To get more details about this feature, please visit OpenSearch Documentation.
The OpenSearch team is actively looking for your feedback and ideas to enhance our new features and capabilities. Please include a description of your use cases with context to help us better understand your feedback.
Some details would be appreciated, what has changed (we already had key/basic/openid/saml) 
Hi @neographikal – the primary change is that before you had an either/or for all those authentication options. This change introduces the capability of being able to use those options simultaneously
@neographikal Please check on OpenSearch Documentation to get more details on this new feature.
The blog post is also great for a high-level overview: Launch highlight: Multiple authentication options for OpenSearch Dashboards · OpenSearch