TABLE ACCESS BY INDEX ROWID BATCHED?

I have noticed a strange access method in one of my test 12c plans, with in-list expansion. The access method is:

"TABLE ACCESS BY INDEX ROWID BATCHED". I thought it was a new 12c feature, but it isn't. I was able to reproduce it on 11.2.0.4 as well. I looked on MoS and came up with documents  1409636.1 and 1585091.1 both mentioning it, but the access path is not documented or explained anywhere. Tracing has shown db file multiblock reads on the index, which means that this is doing full reads on the index and 12c even has NO_BATCH_TABLE_ACCESS_BY_ROWID hint, not found in the version 11G. Intuitively, it's rather clear what it does: reads the whole range of blocks from an