Who are you, and why are you seeming to post these sources multiple times?
This is pure conspiracy theory through "news" sources that have highly dubious credentials.
HN shouldn't be fueling this kind of unsubstantiated speculation.
"If the police seize control of the university, they can monitor / filter all traffic. The whole city can go dark."
I don't think that is true at all - at least not for the last 15 years.
Almost everyone co-located in HK is in a totally different physical location than the University (such as iAdvantage or HKCOLO, near LOHAS Park) and have independent connections outbound to the world.
We, for instance, are physically located inside HKCOLO and have a direct connection to he.net in Fremont, CA. If you traceroute rsync.net in Hong Kong, you typically don't leave he.net.
I'm not sure how seizure (or even shutdown) of the University would affect infrastructure at iAdvantage or HKCOLO or Dyxian, etc.
The posting of this link with this title does not seem to adhere to HN guidelines, even though I see your intentions. I think it will soon be removed/moderated, but meanwhile, I did want to pose a technical question.
I feel that the monitoring of traffic is unlikely. To clarify, this is not about taking a pro-China side, but more on technical aspect. Most modern web traffic happens in some form of encryption (most commonly https/ssl) and some are end-to-end encrypted (various messenger apps). Filtering is certainly possible/likely (just like the great firewall), but monitoring seems difficult (in the case of https traffic) or impossible (in the case of end-to-end encryption... hopefully impossible at least?). There'd have to be hardware-level/low-level trojans planted in individual devices to make that possible. Which isn't to say it's unlikely (from what we've heard in the past few years), but only that it's unlikely to happen with just a hostage of HKIX.
China almost certainly has the ability to perform aggressive SSL interception given their investment in the great firewall. Almost all apps will either fall victim to it, or if they correctly use pinning, simply not load (and cause their users to swap to other apps).
If the police seize control of the university, they can monitor / filter all traffic. The whole city can go dark.