Yep, this is an optional update which improves system stability. There are no new features introduced with this update.
This would be patches for Software that could not update itself so requires the Firmware do it.
So online games whos servers are broke that have been released or are due, or for Ofline software that has now way to update itself as there is no server connection.
O and if Auto update on PS+ is on, these optional updates will be downloaded as turning it on means you agree to download every firmware update...
Might aswell download it since it'll be forced at some point anyway.
PSN ID: Squall_10