The sources declined to be identified due to confidentiality constraints. (File) Hong Kong: Alibaba Group founder Jack Ma, largely out of public view since a regulatory clampdown started on his business empire late last year, is currently in Hong Kong and has met business associates in recent days, two sources told Reuters. The Chinese billionaire has been keeping a low profile since delivering a speech in October last year in Shanghai criticising China's financial regulators. That triggered a chain of events that resulted in the shelving of his Ant Group's mega IPO. While Ma made a limited number of public…