As far as I am aware, there hasn’t been any problems with new user’s ability to vote very early on, unless I’m not paying enough attention. :P
The point of your suggestion is that you should season the users before their tastebuds are introduced to voting, but the voting they do usually doesn’t disrupt or negatively effect the community. It’s not like they spam downvote anyone, and upvotes don’t really hurt the system, even if given out to subpar questions- typically they are giving a new user enough points to post on wall and vote themselves- not a bad thing unless they use these privileges to encourage a ban.