Oh dear - raw nerve touched here (I paid nearly five grand for a new block-paved drive and front garden path last October and still have some drainage 'issues' to resolve).
On the basis of my experience: if left unsealed it seems that block paving does indeed allow very good drainage from the gaps between the blocks. None of the reputable companies I had to quote included sealing in their quotes. But you need it to stop oil etc from staining the blocks - and I think to stop weeds growing up in the gaps. I wasn't able to apply sealant to my drive until April, six months after it was laid. But it immediately showed up several problems of insufficient drainage. The installers fixed most but not all - we're now in dispute.
So...yes I think you need a proper fall and drain arrangements, and to bear in mind that even when you have these you will need to seal or have sealed the drive before you can judge how adequate the installation is. The fall my drive installers looked excellent, even over the top, but wasn't the end of the story, as I've explained.