Does each MatrixBlockModel in an entry have a unique dateUpdated? After doing some experimentation in looping through MatrixBlockModel, it seems that even though each block has a dateUpdated property, this value is never unique to each block, but is shared between all blocks in the Entry.

{% set timeLimit = now | date_modify("-2 min") %}
{% for block in entry.blocks %}
  {% if block.dateUpdated &gt;= timeLimit %}

    {{ block.dateUpdated | date(dtFilter) }}

  {% endif %}
{% endfor %}


If the entry has 6 blocks, and I update one of those blocks and save, the same date will output 6 times for about 2 minutes, then nothing will output.

Can anybody confirm this?
Yes I can confirm, currently the dateUpdated property returns the same datetime object for every block model. It's actually the save date of the entry (entry.dateUpdated) that is saved to the craft_matrixblocks table in the DB. 

Can't say if it's intended to work like this though.