UN Retail is open for business.
I am in HK, I can confirm.
You will need to wait till the trial ends for them to be shuttered I think, as there is a lot of interpretation of law and compliance or non-compliance that needs to be established before anyone is found guilty. UN is a long established company with a good reputation. Having dealt with them a lot over the past three months I can assure you they are well aware of the law and wouldn't sell any gun firing over the limit knowingly. THough negligence isn't a defense, it may gain them some sympathy from the judge.
Hong Kong is a land of law and order after all.