This is a situation where the probability that you unintentionally violate a serious law is high, the probably of that law actually being enforced against you is low, but the consequences if it is are extremely bad.

From an expected value perspective the result has a negative sign but a small magnitude, so you avoid it whenever you can but not if doing so comes at a significant cost. But low probability events with large negative consequences are the category of thing that worries people a lot; other instances in this category are things like plane crashes, child abductions, forcible rape and terrorism. It's not strictly rational to be as afraid of them as many people are.

However, in this case there's also the consideration that the probability of the law being selectively enforced against you has a lot to do with whether the government doesn't like you, so if you're the sort of person the government (or some plausible future government) might try to stick something to, then the "low probability of enforcement" side of the equation changes and you're in entirely different territory.

And we also generally, as a pro-social activity in solidarity with those populations, might want to err on the side of encouraging everyone to behave in a way similar to what those vulnerable populations would have to, to normalize it and make that sort of selective prosecution more difficult. At least as long as we continue to have these disproportionate penalties for what are in practice honest mistakes and everyday behavior.

People parrot that line to sound edgy and virtuous, not because they've thought through the implications.

Why do you have to report a new address when you move? To whom?