whether this is true or not as I was told by delta phone support:
There are some seats blocked off on CRJs and can only be assigned at airport checkin or gate agent. What has happened is that all the available(not blocked seats) have been taken and delta blocked off some seats but then some how released a few more seats to sell i suppose. messed up logic? most definitely.
I dont think you will be VDB'ed or IVDB'ed youll get seat assignment at check-in.