Multiple newer parents I've met (in Australia) have practiced complete avoidance of such serious potential allergens. The idea seems to be that a very young child may have a reaction, but not be able to tell you and just cry or go red - as per usual at that age, so you probably don't realise it's serious until it's too late.

They gradually introduce these foods later. Maybe too late, if the idea of early exposure is accurate, but it's very much a case of "can't be too safe" when I asked them.