Interesting the Bethel letter never once that I saw made the claim the blood rule or any other rule was made due to "spirit direction". The Bethel writer wrote that the Governing body gives the blood issue careful and prayerful consideration, and listens to arguments that debates the pro and the con "factors".
For some decades now "the faithful and discreet slave" has been giving the matter of blood usage in medical procedures careful and prayerful consideration in the light of the Scriptures. Each time this matter has come up for review by the "slave" class, taking all pertinent factors into consideration, including those discussed in your letters, the basic conclusion has been the same, that accepting a transfusion of whole blood, or of it’s four recognized components red cells, white cells, platelets, or whole plasma would be clearly contrary to the Scriptures. (Watchtower Jensen blood letter May 30, 2001 p.4)
The Watchtower letter writer has the audacity to say the decision to allow fractions was made "in the light of the Scriptures", without being able to supply one supporting Scripture. One like me would have to conclude they are guessing again like they admit doing with dates set for Armageddon.