No, it is unlikely that they would come after you for it. Since there is no return being filed under his social security number in 2021 and the 2020 tax return his date of death was reported. Your father has no filing requirement for 2021 since he passed away in 2020. There is nowhere to report the 1099-C.
If you never receive a 1099-C from Wells Fargo, there is nothing to be concerned about.
My suggestion would be if you receive the 1099-C, put it with a copy of the death certificate, and if you receive any communication from the IRS concerning the 1099-C, then respond to the letter with a copy of the death certificate.
