Actually the history goes back way further. If anyone's curious:
- First release of StarOffice was 1985. It was a closed source commercial word processor. https://en.wikipedia.org/wiki/StarOffice
- Sun, now Oracle, bought StarOffice in 1999 and released it as OpenOffice the following year
- Oracle bought Sun in 2010, and the community fragmented because nobody trusts Oracle
- In 2011 LibreOffice was forked from OpenOffice
- Later that year Oracle gave up on OpenOffice and gave it to Apache, but that version (Apache OpenOffice) is an orphan that nobody maintains anymore.
So yeah, there's probably still LibreOffice code that dates back to 1985 in some form!