OpenOffice was a dying project. Sun had been fairly unresponsive to the community and unwilling to fold in community changes. When Oracle bought them it got worse still. Projects like Go-OO started up, which wasn't so much a fork as a patch-set. OpenOffice was looking sad and it looked a lot like the best known FOSS suite was doomed to splinter and die.
Then LibreOffice was started to sort this all out. A real fork, a new name, it folded in Go-OO and other community improvements and committed to proper governance, addressing technical debt etc.
A year or so later, Oracle 'gifted' the stunted and now somewhat left behind OO.o to the Apache project. A few corporates got behind it, but it had no community traction, and any small improvements that did get rolled in were very quickly adopted by LO, where flow the other way was almost non-existant.
This is not really a story of licensing as much as it is community mismanagement by Sun, and active hostility from Oracle.