This will, no doubt, backfire on the Austrians. I can't help but believe that this will spread DI's point of view even further. If he was allowed to speak freely, and his thesis was opened up to critical reviews from his peers, the end result would probably further reduce his reputation to that of 'ultra crackpot'. But now that an academic is headed to jail (simply for having a disagreement with history) it will gain him sympathy from others, possibly even some Jews.
Just saying it will get you prosecuted.
The Austrians have put a lot of fear into the process, and with no effect other than to eliminate even critical comments of the man.