TNEW 'Sold Out' message question

Our winter season is announced and single tickets for all performances go on sale Aug 4.  One series are showing 'Sold Out' message ( indeed there is no seats available on a seat map in Tessitura). Shouldn't it say 'Not on Sale' until Aug 4 and then 'Sold Out'.  What is the logic behind the scenes ?

Thank you,

Sabina