I think you should still have a calling strategy that time of year. It?ll be hit or miss on if they are still vocal for the first season, but last year there were a ton of reports of them still bugling during that time.
I wasn't in 63, but last year the Unit I was in for 2nd rifle (I think about the same time as first rifle is this year) the bulls were still bugling their heads off and there was certainly a lot of rutting activity going on.