The NHL has put out the following statement regarding this matter:

NHL Further Delays Flames’ Return to Play; Avalanche & Panthers Also Shut Down Through the Holiday Break
NHL Public Relations December 17, 2021
NEW YORK (Dec. 17, 2021) – The National Hockey League announced today that it has extended the period of game postponements for the Calgary Flames through their game previously scheduled for Dec. 23 against Seattle. Additionally, due to concern with the number of positive cases within the last two days as well concern for continued COVID spread in the coming days, the Colorado Avalanche’s and Florida Panthers’ games also will be postponed at least through the scheduled completion of the League’s Holiday Break in the schedule on Dec. 26. The decision was made by the NHL’s, the NHLPA’s and the Club medical groups.   A decision on when each team’s training facilities will re-open will be made by the League and the NHLPA in the coming days. The League is in the process of reviewing and revising all three teams’ regular season schedules.   The Flames’ postponed games to date include: Dec. 13 @ Chicago; Dec. 14 @ Nashville; Dec. 16 vs. Toronto; Dec. 18 vs. Columbus; Dec. 21 vs. Anaheim; Dec. 23 vs. Seattle.   The Avalanche’s postponed games include: Dec. 18 vs. Tampa Bay; Dec. 20 @ Detroit; Dec. 22 @ Buffalo; Dec. 23 @ Boston.   The Panthers’ postponed games include: Dec. 18 @ Minnesota; Dec. 21 @ Chicago; Dec. 23 vs. Nashville.   The Flames, Avalanche, and Panthers organizations have followed and will continue to follow, all recommended guidelines aimed at protecting the health and safety of their players, staff, and community at large as set by the NHL, local, state/provincial, and federal agencies.