Pretty sure this argument already went over at the wizards boards and they got a designer to say they didn't intend for psicrystals to work that way. If the DM allows it that would be useful, though.
What they said was "while we didn't intend for it to work that way, as the rules are currently written it explicitly does".
Even if he will just allow you to swap out the Alertness feat for Mindsight (once you hit 5th level), it can be incredibly useful. There are a couple of "tricks" that can be used to do this.
Even without mindsight, psicrystals can make awesome scouts. I'd definitely find out about how you replace one, though. If he says you take the XP hit as you would for losing a familiar, I might not risk it.