It's pretty common for Western companies to adopt this holding firm type structure, as the article points out it echoes Google's restructuring to Alphabet.
It cannot remain a holding company if these businesses are expected to IPO though, can it?
Sure it could. There's nothing (other than the government, presumably) stopping them from listing six separate companies with, for example, dual-class share structures that leave substantially all voting power to Alibaba Holdings Ltd.
They can keep a stake in the companies after the IPOs, even higher than 50%.
Although you could say that the outcome could be considered the same, the motivations behind it are completely different, as the parent comment mentions