This will allow them to undo the policy without actually undoing it.
I think your assessment is correct. I don't think Watchtower is worried about potential civil lawsuits or criminal prosecution related to its position on blood.
I've often read ex-JWs opine that Watchtower would end its blood taboo were it not for fear of lawsuits. Yet to this day I've yet to see anyone express a legal argument supporting such an opinion. The position Watchtower holds is a religious one which essentially means it can relax it to allow blood transfusion in a heartbeat without fear of serious civil lawsuits.
My view is that Watchtower has resisted relaxing its religious position to allow blood transfusion in order to protect its religious viability rather than its legal position. The fallout would be enormous were Watchtower to suddenly change its blood taboo to allow wholesale transfusion of blood. On the other hand, Watchtower in effect does let JWs make wholesale use of the donor blood supply but it's done so with such convolution that JWs use massively from the blood supply yet think they abstain from blood. (See: Over 96% Accept 99%! )