Given what you indicated, I'm assuming they're healthy. The risk for catching COVID-19 and dying is extremely low, even amongst the elderly if they're relatively healthy.
The largest deaths (50% or so in NYS) were in nursing homes where people are already frail and sick and after a hospital visit NYS forced them back into the nursing homes to re-infect the rest (less people reduces the state expense on these facilities) as well as to reduce reimbursement costs for Medicaid through the hospitals.
Given your parents did so well for themselves is an indicator that they worked hard, they didn't excess, they probably didn't smoke or drink (at least not much). That is a great predictor to live to 100 even with COVID-19.