It probably won't ever be serviced or upgraded, for several reasons:

It's orbiting at the Earth-Sun L2 Lagrange point, with a perigee of 374,000 km

While we can put astronauts in space, we don't currently have any orbital vehicles with on-orbit satellite maintenance capabilities, since none of them have airlocks

The latter could very well change over the next few decades though, and the former may become economical, so I guess it can't be entirely ruled out.