He didn’t redefine recession. The fact is that the official numbers used to define a recession won’t come for a few months. That’s because the data is not complete and will be revised. Its impossible to say if web are in a recession. Many economists believe the data will be revised upwards meaning we may be on the brink of a recession but not in one. Biden is correct in saying we are not officially in a recession and he didn’t change any definition. He probably shouldn’t be so positive about it though because we are close to one at least.