Where are these theories of how a hypothetical future CBDC come from? Is there an official announcement from the Federal Reserve about how they would like it to work? A committee hearing in Congress where this is discussed?
Eswar Prasad, WEF Annual Meeting of the New Champions, June 2023
The above has some chatter about non-US nations exploring the expiry/programmability aspects.
Also, nothing stops people from buying the goods in question by using a payment service provider/bank that provides a layer on top of the CDBC and automatically circulates the money for you behind the scenes to avoid the expiry.