That is all true, but another thing to consider is that they haven't even finished the software for Powershare yet. For example, the Cybertruck can't enable the on-board outlets while charging, via either AC or DC, but Drew says that a future update will allow them to be used, but at a limited power level. So, they may not want to expand the number of Powershare capable vehicles until they have things more finished, tested, and polished.I doubt it also, but the 48V part of the PCS is a separate block. They could copy Cybertruck's charger module and carry over the 16V converter, or adjust the new ones to 16V. Of course, they wouldn't need 800V compatibility.
Cybertruck's planer inductors could be a cost savings. Also, active switching could be more efficient than the diodes previously used.
And the Powershare Mobile Connector manual doesn't even mention the output potential that it is supposed to have.