This isn't CZ's view on the BTC halving, this is the common knowledge or view about BTC halving based on past events, and any person who spends a little time to read about the halving and what happens before or after the halving would know this. If history repeats itself, which it usually does, it could follow the same pattern again.
I view this as a too-know coming from you, even if billions know a thing, once it's coming from a particular person, what do they call it? Your view or general?
Besides, this is regardless of people's knowledge, a piece coming from him directly could influence some people who didn't want to give it a shot initially or are confused with tons of cabbage online. That makes it an individuality affair which is more powerful and influencing than each other.
You might want to further read from this user amongst others who understand the situation better:
I have the same experience as CZ had. It maybe a common knowledge for those people who are in crypto space for long but for newbies it's not. Maybe the goal why CZ posted this is because he want to educate newbies or those who didn't know about this info. This can motivate them into investing into bitcoin as early as now and not expect a sudden jump in price after the halving. It's a good information that newbies should learn.