Yes, your uncle should get the Recovery Rebate Credit. Per the IRS, a payment won’t be issued to someone who has died before January 1, 2020. However, eligible individuals who died in 2020, should claim the Recovery Rebate Credit their 2020 tax return.
The IRS‘s actions here make no sense as I have been saying all along. There is nothing in the law that prevents payments to a deceased person and everything in the law that says that a person who is deceased after January 1, 2020, and who will be filing a final tax return for 2020, will be an eligible taxpayer for the recovery rebate. There was never justification that I could see for the IRS to have made the administrative decision that deceased persons were not eligible for the early payments.