It's being tracked, but not by the "Minor Planet Center".
It's just not being published on a certain curated list by the MPC.
>“This incident, along with previous NEOCP postings of the WMAP spacecraft, highlights the deplorable state of availability of positional information on distant artificial objects,” the MPC fumed when it retracted 2007 VN84. “A single source for information on all distant artificial objects would be very desirable.”
I'm not sure if it was the lack of trajectories or the unusual orbit which caused the automation issue at MPC.