Pioneer 10 and 11, even if they were functioning, are not headed towards the new object.

Pioneer 10 will pass near Aldebaran in Taurus in about 2 million years and Pioneer 11 is headed towards Aquila the Eagle.

http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PNStat.html

And for the Voyagers:

Two more NASA probes that built on the successful missions of Pioneer 10 and 11 were the Voyagers. Voyager 1 also visited Jupiter and Saturn and is presently sailing towards the outer limits of the solar system. The craft is headed towards the constellation Camelopardalis (The Giraffe), a star of which it will fly close to in about 300,000 years.

Voyager 2 flew past Jupiter, Saturn, Uranus, and Neptune during its Grand Tour of the solar system, but the probe is now headed towards the star Sirius in the constellation Canis Majoris (The Big Dog). Sirius is the brightest star in the night sky, and Voyager 2 will pass close to it in about 160,000 years.

Both of the Voyager probes are still transmitting and are expected to continue sending signals to Earth until around 2020 when their power sources decay.

http://www.aerospaceweb.org/question/spacecraft/q0225.shtml