That's a recent change. Curiously, it hasn't been a result of changes in ISO rules, but just interpretations of them. Committee Drafts are still secret, but Working Papers, effectively identical, are not. Likewise, published Standards. Committee mailing lists and issues lists exist entirely outside ISO's domain. Even voting rights make much less difference than one might think; actually doing the work carries more weight, because when in doubt, voters vote with whoever seems to know more, and most voters are always in doubt.