No, that auto rental is not blocking the other ones. Because all cards with less than 80k CP will skip that bid and go straight to the next one. And I personally rented out cards to a few of those bids in position 2-4 a few hours ago.
The only real downside is that the bid is sitting there at the top of the list and it's wasting space :)
RE: Big exploit on Automatic rentals blocking every rentals