In prior filebeat doc (at least in 7.5.0) the output index section stated:
The index setting is ignored when index lifecycle management is enabled. If you’re sending events to a cluster that supports index lifecycle management, see Configure index lifecycle management to learn how to change the index name.
This appears to have been true thru 7.17, but in 8.1.2, the name of the ilm.rollover_alias doesn't seem to be used for output, it reverted to the default ILM filebeat index name. The 8.1 doc still has the forward reference to Index lifecycle management (ILM) but that part no longer says it will change the output index name. It appears I now will have to put the index: name in all output sections.
Has anyone else noticed this? Did I miss it in breaking changes? There are SO MANY release notes to read, I can't keep up.