Attitudes toward server version disclosure are not unequivocal. Today it's easier to run a scanner for all possible vulnerabilities for all kinds of servers, versions and backends hiding behind proxies. To be clear, you are not hiding by hiding the version of nginx.
On the other hand, the Server header allows public services to collect statistics about the products used on the Internet. This also allows you to track the version of your nginx if you have multiple copies running.
In addition, this directive can be changed to suit the needs. Therefore, I would say that this question is more relevant to the discussions instead of the issues.

Thanks for converting it to a discussion.

Today it's easier to run a scanner for all possible vulnerabilities for all kinds of servers, versions and backends hiding behind proxies. To be clear, you are not hiding by hiding the version of nginx.

I agree with you in this point, there is always a way to gather information. Completely hiding the server version, takes away a lot of important information though. I'm fully aware that there are other fingerprinting methods but the most common fingerprinting methods are somewhat defeated.

Removing this information likely would make a lot of setups somewhat harder to check for vulnerabilities based on the version.

On the other hand, the Server header allows public services to collect statistics about the products used on the Internet.

Without you mentioning it, I would not have it considered it to be so important. Thanks for pointing this out.

This also allows you to track the version of your nginx if you have multiple copies running.

In my opinion, if you have multiple versions running, may it A/B-testing, load-balancing to an older infrastructure, etc. people should be experienced enough to be aware that some configurations need to be adapted.