The flights have been intentionally zeroed out due to lack of sufficient demand and at this stage it is unknown until when (the fact that you see availability as of 26.10 does not mean the flights will actually operate). Factually speaking, OS is still grounded and will commence resuming its flight program as of Monday, 15.6. Here is a list of that flights that will be initially operated:
https://www.austrian.com/Info/Flight...start2020.aspx