That's correct. Initially the paliperidone palmitate will accumulate in the muscle, and then will diffuse to the body fat. But don't confuse a compound being dissolved in fatty tissues, with being chemically linked to a fat molecule. They are two seperate things.
The paliperidone palmitate - which is what was injected - is not the same as "free" paliperidone. It's composed of paliperidone, with a big fat molecule glued on, making it want to dissolve into fat. As the paliperidone palmitate slowly diffuses back out of fat into blood, enzymes (called lipase enzymes) in your blood and tissue break it down, into palmitic acid (a fat), and paliperidone (the active antipsychotic). This is why the effect isn't instantaneous after receiving an injection, actually!
Don't worry though, as the fat molecules can't get re-stuck on there. And paliperidone can't last forever in your blood stream. Any paliperidone that is liberated by lipase enzymes will eventually be metabolized and excreted. As time goes on, there will be less and less paliperidone palmitate remaining, so levels of "free" paliperidone will fall. Eventually there will be only traces left, and you will be back to normal.