According to a post by the Around the NFL staff on the league site and reporting by Tom Pelissero, players will once again have the option to voluntarily opt out of playing in 2021. The deadline to make the decision to opt-out, which cannot be reversed once made, is next Friday:
Only players who executed their contracts prior to Oct. 1, 2020, are eligible to take a voluntary opt out, so 2021 rookies aren’t eligible. If a "Higher Risk" rookie opts out, the club still owns his rights. All opt-out decisions are final.