As Pinfield is still shown on the WRXP website (albeit less prominently than in the past), it appears he may still be employed there. Stations tend to be very quick to remove former staff members from their websites. Nathan's guess that he is using up his vacation time while he still can, seems plausible.
I still find it weird that WRXP announced an ambitious rock concert 1 day before the news comes out that it will be going off the air soon. It seems inconceivable that the station's management had no inkling of the news at that point. Emmis could have also stepped in and prevented the concert announcement.
Perhaps WRXP will soldier on into mid-September, when the concert is scheduled to take place? If a news or news/talk station is planned for 101.9, it will probably take a while to hire staff, and set it up. It's not like flipping to another music format, and simply playing 10,000 songs in a row, with no dj's.