Think of all the leaked WT classified information that has come out just on this site, or the leaked pedophile information that has gotten into the hands of lawyers. Do you really trust the WT to keep your information secure? And you would have to trust, not just the WT corporation, but everyone at Bethel who has access to that information.
IMO, it would be far safer to think about it for a while. You can always give your permission later (than May 18th), just as you can also cancel your permission later. But once they have your info you can only trust that they will delete it.
That's my opinion anyways. ("No choice was given . . ." - Sounds like the elders are in a bind between what the WT wants and being fair with people. This is their way of solving that problem.)