Read the rules ... the money must be put back in the same type of account ... the law did not mention ROTH conversions were allowed ... if you want to then make a conversion it would be a separate situation from the repayment of the CARES distribution.
https://www.irs.gov/newsroom/relief-for-taxpayers-affected-by-covid-19-who-take-distributions-or-loa....
The CARES Act provides that qualified individuals may treat as coronavirus-related distributions up to $100,000 in distributions made from their eligible retirement plans (including IRAs) between January 1 and December 30, 2020. A coronavirus-related distribution is not subject to the 10% additional tax that otherwise generally applies to distributions made before an individual reaches age 59 ½. In addition, a coronavirus-related distribution can be included in income in equal installments over a three-year period, and an individual has three years to repay a coronavirus-related distribution to a plan or IRA and undo the tax consequences of the distribution.
