Does ES restart is needed after basic license applied

I see this when try to update basic license to my ES

    "security": [
      "The following X-Pack security functionality will be disabled: authentication, authorization, ip filtering, and auditing. Please restart your node after applying the license.",
      "Field and document level access control will be disabled.",
      "Custom realms will be ignored."
    ],

do I really need restart my ES? what will happen I don't.

You don't need to restart your Elasticsearch cluster when you switch to a Basic license. That message is just letting you know exactly which features will be disabled when you apply the license.

Thanks