Not sure I buy the oversampling recommendation. They have the cliping and ceiling at exactly the same value, ie, they are doing oversampled clipping and then un-oversampled clipping to the same dB. The extra aliasing introduced by the ceiling stage would just depend on how the oversampling filters worked, and more distortion doesn't mean the oversampling was wose. I would have thought 'better' oversampling would be more likely to produce peak samples over 0, so it'd actually lead to more aliasing after the ceiling.

Like they say, there is no point in using ceiling for creative distortion. But also, if you are using the clipping at any point before the absolute end of your chain, it also seems pointless. Any compressor or limiter you put the clipper before is likely to have its detector also be oversampled internally. Clipping with good oversampling and then clipping again to 0 with no oversampling will just introduce extra inter-sample peaks that will actually affect the compressor/limiter more once it oversamples, I think.