Putting aside any possible concerns related to authoritarianism...

A problem with social credit systems is that its implementation can easily backfire. I really hope they are implementing various parts of it only after serious localized testing.
There is a reliable result in behavioral economics that if you reward/punish people for things, they stop thinking about it in moral/ethical terms. They quickly start gaming the system, even if they had better behavior before it was implemented.
What that means is they have to be very carefully about the details. Perhaps something like a system where repeating the same bad behaviors has escalating costs.

Also making details publicly available has a risk, since low social credit score could also be used to recruit scummy people for crime, unscrupulous business, or even towards political ends.

And I really dislike the way it places value on publicly visible good behavior, ignoring the so often unmeasurable good that people can do for each other.
Such a system could also easily become terribly ableist. Or even classist, in that rich people have more time and energy outside of work for dogoodery.

I am not really opposed to it, but they have to test and think about these things carefully before introducing it on a larger scale.