The negatives are that it does mean that it's now possible to solve a block, but find that there are not enough transactions on the network to create a valid block, so your work has been wasted.
Just to make sure that we are talking about the same thing: I assume that you need to know all transactions that you include into your block before you start the proof of work. Please correct me, if I'm wrong. So I do not see the point of
wasted work.
Cheers, and thx for the chat so far
