I flew from EWR to IAH two saturdays ago and it seemed that no R seats were released until the day before. I was not near a computer most of the day so I couldn't check in earlier, but miraculously there were 4 seats in R when I actually did check in. I really wish that the process that releases the R seats would be immediately followed by the EUA process... unless someone has to manually release the R seats, but that doesn't make much sense to me.