It's alarming that new COVID cases are increasing at the rate that they have in the past week. This strain is making more vaccinated symptomatic, but it's still unclear whether this new strain is as virulent (deadly) as Delta. I think a lot of sports leagues are going to play it safe until there's more information.
It's a numbers game though. Hospitals will be stressed but not totally overwhelmed in areas with high rates of vaccination. This new strain is going to play out exactly like Delta did; lots of sickness and death among the unvaccinated and hospitals being overwhelmed in areas with low vaccination rates.
Get your boosters ASAP if you're last shot was over 6 months ago. The vaccine still protects against serious disease and death very well.