In brief: Another service is joining the Google graveyard, for better or worse. As the latest in a long series of Google service shutdowns, Cloud Print will be terminated in just a few short days, meaning it will no longer be accessible for ChromeOS customers or others.
Most internet users have probably never used Cloud Print a single time -- it was primarily designed for ChromeOS customers who had limited or no access to traditional printers years ago.
However, now that ChromeOS boasts much broader support for printing devices, Cloud Print has effectively become obsolete. It still has a few unique advantages, such as the ability to share your printers with friends, but for the most part, there's no reason for Google to keep it around.
In other words, at worst, Cloud Print's termination will be a mild inconvenience to some. For others, even ChromeOS users, you'll simply need to remember to switch your default printer to a different device -- easy enough.
The exact date of Cloud Print's shutdown is December 31, 2020, which is just two days away. If you loved using the service for one reason or another, be sure to get all your printing tasks done before New Year's Eve.
If you're unsure how to switch away from Cloud Print, Google has a full "migration" guide to help you out.