Hi, I'm not sure I agree - the officale_name tag can be used by itself and isn't necessarily a fallback tag like alt_name or similar.

The name of these overpasses suggest they're what would be used in official documents e.g. by the government highways department and are not colloquial names (try using "South 85-South 280 Connector Overcrossing" in a sentence :) ). In this case official_name is appropriate although there is also bridge:official_name, which I think might be more appropriate.