Absolutely true. It’s extremely rare. In fact, this is likely the first time a coronavirus has killed this many people before. Of the 7 coronaviruses known to infect humans, 4 cause mild to moderate respiratory symptoms and are part of the over 200 viruses known to cause what we called the “common cold”.
SARS-CoV-1 (SARS2003) is another coronavirus known to infect humans. However, it didn’t spread particularly well and if quickly made people very sick, so they generally stayed away from other people and went for medical treatment.
MERS-CoV (MERS2012) is another coronavirus that infects humans, but it was even worse at spreading than SARS 2003 and it killed people very quickly.
So yes, all evidence points to this being the first time a virus in the coronavirus family has emerged that’s been able to spread effectively enough to infect a lot of people, but still deadly enough to kill a lot of people.