The whole situation is bad, everybody will agree. But it will get worse and you have authority to change this by simply arranging to pay back the disgruntled clients that you can for now, and assuring others that they will get their money back in due course.
If he is insolvent he cannot do this without the agreement of all of his creditors - he'd be committing an offence under insolvency law if he did and the payments would be subject to clawback.
A clear statement from Andre about whether he intends to seek the protections of insolvency law would be useful but he's certainly not obliged to provide that information in advance. While it's not especially costly to pursue money through Qld's Small Claims Tribunal (they deal with claims of up to $25,000), a judgement needs to be enforceable to have value - voluntary or involuntary insolvency proceedings would affect the value of any judgement obtained. Bear in mind that a debtor can ask the court to order that the judgement be paid in instalments so obtaining a judgement does not guarantee getting the total amount you are owed quickly.
A few people have posted the amount of money they have tied up in WBX in this thread. If more people did that, it would be possible to get a clearer idea of whether individual actions are worthwhile or whether Andre's creditors' interests would be better served by initiating insolvency action against him now rather than hoping the situation will improve. Of course Andre may owe significant amounts of money to other creditors too - it's impossible to know that without some kind of action which forces disclosure of his true financial situation.