Considering that the only ones really found and studied were on the Mary Rose (and nobody is really even sure if they were finished or not) its hard to say.
Where on earth did you hear that?
Good grief... I agree with Ian... where did this come from??? The Mary Rose Trust even took a few bows and drew them to full draw on the tiller to look at their shape and draw weight. Why on earth would Henry VIII have a warship full of unfinished warbows???
As far as draw weight goes... yes, EWBS states that min is 70#@32". A good starting point, I believe. Some people can't shoot more than this, especially initially. Personally, I think a warbow starts at >80#@30". I also think it depends more on bow style, shape, tiller, and how it's drawn and shot. I've made 85# target longbows, and 70# warbows, and they're very different beasts.