The article is entitled, "Remember Those in the Full-Time Service."
It would be more honest if entitled, "Remember Those We Designate as Being in Full-Time Service."
In contrast to the WT's selective "Full-Time Service," the great crowd is described in Rev 7:15 as "rendering [God] sacred service day and night in his temple." Disciples of Jesus are described by him as those who, "disown [themselves] and pick up [their] torture stake and continually follow me."
The whole premise of the article reeks of Luke 18:9 - "But [Jesus] spoke this illustration also to some who trusted in themselves that they were righteous and who considered the rest as nothing."