Yes. Parquet files do not support deleting or adding rows, since they are immutable. So adding or removing rows requires rewriting the file. The way I see it, using this optimization we can mark rows as deleted at delta table level without having to rewrite the underlying parquet file.
I have fond memories of Dragonlance. Spent good part of my childhood reading every Dragonlance book I found from the library. The chronicles and the legends (the ones with the twins) were awesome.