These new guidelines will likely have an impact on the NHL. The NHL is currently paused due to a rise in COVID-19 cases but teams are expected to return to play on December 28th. The NHL implemented more stringent protocols for teams prior to the shutdown in order to curve the spread, such as additional testing and a return to mandatory mask requirements.
Recently, the NFL changed their testing requirements for fully vaccinated, asymptomatic players; who are now only tested if showing symptoms of COVID-19. The NHL currently only has 1 unvaccinated player (Tyler Bertuzzi in Detroit) and we have seen players on Canadian teams such as: Tyler Myers and Connor Hellebuyck show desire for the NHL to take a similar approach to the NFL.
Currently NHL players have had to follow public health guidelines and isolate for 10 days if they test positive for COVID-19. The new guidelines could lead to changes for at least the American teams, but the NHL will have final say in that.
The main issue with implementing these changes is that the NHL has 7 Canadian teams which makes it much harder to take a similar approach to the NFL for travel reasons. These new CDC guidelines are only for the US and Canada has had a very different mindset with how it has handled the Omicron variant.
As a result of the NHL being an international league, it's uncertain how these new CDC guidelines might impact the league. However, the NHL is expected to review their COVID-19 protocols on January 7th and these new CDC guidelines could be an interesting discussion topic.