joachimM, interesting articles you attached to your post. The "Wood Conservation" article states "In anaerobic waterlogged environments, however, wood undergoes profound chemical changes and alterations that result in a significant loss of strength while retaining overall shape and form." It doesn't state how long this "significant loss of strength" takes to happen. Do you have any research data on the time line for these changes to take place?
If it starts to take place fairly quickly, then water curing wood seems like a highly undesirable process. Anything that weakens wood is not good for a bow from my point of view. Perhaps some of the chemical and physical changes that take place in this process do help the resonance of wood which is so highly desirable in a violin, but I still haven't seen any evidence that this "curing process" will help a bow preform better.
It does make sense that storing a log or stave under water could delay shrinkage and checking of the wood until you have time to properly process and dry the wood. Beyond that, I don't see much advantage.