I think people are simply highlightling that there are two ways of "sitting out a contract":
(a) sit out contract whilst not stirring things on social media
(b) sit out contract whilst stirring things on social media
Yes, it could be argued that the club aren't treating him "fairly", but a player has two options if he thinks he's being treated unfairly.... lower himself to his perceived level of the club (i.e. tit-for-tat) or rise above it and maintain a mature and dignified silence. Austin appears to have taken the first approach. Nothing wrong with that of course, his choice.
Yours observingly...