Thanks for your answers @ycui & @scott.
@ycui yep. I was aware of it. I think that this translates to the punish synapses code, right? Nevertheless, biologically speaking LTD seem to be applied pervasively (no matter if the cell was predicted or not).
As @scott suggest, such punishment (if is too high or frequent) might kill useful concurrent "prediction paths". The core issue one might think is if this is also the case of the biology. Intuitively LTD is equivalent to say that no cell will be shared by multiple prediction paths. In other words, the constant appearance of a sequence might "kill" another partially shared sequence. In summary, apparently there is a contradiction between parallel predictions and LTD... Probably segment reuse is enough for practical uses of TM. Nevertheless, this apparent contradiction is a bit itchy
PD: Still in proximal dendrites (L4 an L2) might be useful (and not counterproductive, since there is no prediction) to perform LTD. Some simple experiments I did seem to suggest that.