the best tracker of how quickly/slowly airline passenger traffic is responding to COVID cases, vaccinations, etc. is the TSA daily count which compares 2021 with 2020 and 2019.
www.tsa.gov
I think domestic travel will bounce back quicker than Massport's estimate in January, if only because the pace of vaccinations is accelerating.. California has announced that nearly all restrictions end on June 15. However, because Europe lags badly on vaccinations, I also think the number of passengers crossing the pond will be depressed until 2022.
FWIW, Jamie Dimon, head of JP Morgan Chase, issued his annual letter yesterday. He expects an economic boom through at least 2023..