Without knowing anything about it, I would posit that degradation accelerates the longer the battery is kept above some threshold temperature.
So, a heavy-burst+low results in a sudden high temperature then settling into a lower temperature. Steady flow keeps it at moderate temperature (above threshold) for a long time.
The paper notes there are multiple degradation mechanisms at play, and they are influenced by different factors, such as age, cycles, depth of discharge, state of charge at rest and so on. Hence the non-trivial response to more realistic discharge curves.
However they also note more material studies are needed to understand these mechanisms better.