I think the policy is one ultimately about competition for students (from Mainland and beyond) and competition for resources.

For insiders with hearts, it is a rearguard battle: trying to get something good out of this necessary evil. Without good students and research resources, the survival of the university itself is threatened and there is no room to talk about visions and ideals. Then, justification and moral high ground are sought. You can call it conspiracy or whatever, if you like, but it doesn't need to be.

The bases for the moral battle:

Economic, educational and cultural merits of the language policy:
-Students will have better English/Mandarin language skills. (doubtful?)
-Students will be seen by employers as having better English/Mandarin language skills. (more probable)
-More students recruited from outside Hong Kong.
Economic benefit: “social capital” for students to compete in society and in China (whether it’s good is of course debatable)
Educational and cultural benefits: more exchange among students from different backgrounds
-Attract talents to Hong Kong (Do they have commitment to local society, particularly if they do not try to master local language?)
-Contribute to the assimilation of Hong Kong into China (whether it’s good or bad is debatable)

Drawbacks:
-Elitism: beneficial only to elitist students who can benefit from English education (whether it’s good or bad is debatable)
-Poor education outcome of local students by not using mother tongue as MOI
-Hegemony of English and Mandarin
-Forgoing the mission of transforming outside knowledge into local knowledge using local language
-Forgoing the advantage of Cantonese as a hybrid language between Chinese and western languages

What debatable are:
-Should the purpose of higher education be absorbing more “human capital” for the academia and society as a whole or as ladder for social mobility of local students?
-Should higher education be serving national and international capitalist/academic efficiency or local equality?
-Should higher education be about generating more knowledge or should there be social mission of social mobility?

Are the merits based on academic and economic efficiency really “moral”? Or do we need to accept that it is immoral, but necessary and inevitable? Just don’t dream of having the cake and eating it.

Supposing that judicial review be granted, we need still ask the question, How the court may rule on the merits; which must depend, I suppose, on what the drafters originally meant by "主要" or "principal."

Now, it may be said, at the outset, that it would be senseless to force instructors of English, or English literature, to use Chinese as the language of instruction. So, the "principal language of instruction" in the Department of English simply could not be Chinese. But what of the Faculty of Medicine? In theory there is nothing against the use of Chinese in teaching medicine. Will the court rule that the principal language of instruction in that Faculty must be Chinese? If so, what will it imply then? If an instructor speaks Cantonese in class, but insists on using textbooks written in English, and on examining the students in English as well, will such practices contravene the judgment?

Suppose after the judgment a GPA student is distressed by the fact that in more than half of the required courses of his major he is given a reading list containing readings, more than half of which are written in English; a situation which I suppose is no mere fancy. Will he then have standing to sue the CUHK, on the ground that the latter has, in allowing his Department to list so many required readings in English, contravened the judgment?

I suppose that he being directly affected by departmental policy, should have standing. But if his case be allowed, then the court will be forced to rule in great detail what it means, for legal purposes, that the "principal language of instruction shall be Chinese."

I am not sure whether asking the court to rule on this particular matter is necessarily to the long term benefit of the CUHK. Besides the question of whether a review might be granted by the court, meticulously discussed in the article, it is no less imperative, I mean, to consider what the consequences might be if the court be inclined to rule this or that way.