There is plenty of Oxygen to handle a single lift. Just not a rapid full set at near max weight. The specific transition point varies based on a wide range of factors,mbit simply waiting between each individual lift is enough to stay aerobic.

I'm skeptical about how aerobic weightlifting can be before it isn't really weightlifting, but also not too interested in arguing. Some weightifting protocols such as German volume training do seem like they must contain a decent aerobic proportion.