SP3 hasn't been released. I would have received plenty of notifications if that were true.
This is the
pirate version of Windows dubbed Windows SP3, just like the previous Windows XP Bill Gates edition...
The old SP2 flavouring was getting old so they made an SP3 one by including tons of software.
If someone wants a near SP3 version of Windows XP, just slipstream the various updates into the SP2 setup files.