I think you misunderstood.
All antibodies are short lived, only about a month or 2.
You quote said, "A small population of antibody-producing cells, called long-lived plasma cells", persist in the bone marrow.
These are T-cells and B-cells, and are not antibodies. They are the long lived cells with memory and the ability to make anti-bodies as needed.
The wording is conflicting. It said these T-cells and B-cells, quiescent, just sitting in the bone marrow and secreting antibodies."
And they can't be quiescent and secreting antibodies at the same time.
What they really means is that they normally are NOT secreting antibodies, but start up secreting antibodies as needed upon reinfection.
Antibodies actually are harmful when not needed, so you don't want them when not needed.