This may relate to something that was reported earlier elsewhere - that the authorities are tightening enforcement about which education institutes are be able to provide the JW201/JW202 documents that are needed when applying student visas.

I was suspecting something like that too, but for us it was was 7 weeks + 2 days, or 51 days. Felt like an arbitrary number, or a glitch in the application's database that forced everyone/some people to re-input.

That sounds like something the covid would say too...

Did they mention when exactly the policy changed?

I would suspect this change of policy relates to the corona virus being more dangerous for older individuals.

If someone requires a student visa to stay here, they may think that the person has no other reason to be here and want to avoid the health risk.

Me and my wife as well had to fill the form again in Monday this week, by surprise when we were entering subway station.

I wouldn't put much emphasis on how people fill the forms, but the tracking aspect.

I assume that it could pop a red (or at least yellow) card out of nowhere, on suspicion of having been around an infected person within so many minutes or hours - in same store or whatever, without you knowing anything about it.

In that way, yeah you could be healthy in the morning and healthy in the evening too, but the system would know you to be a potential carrier better than yourself.