I havent looked at my Airtronics yet to see if it has that feature.  Never even thought about it to be honest.  But now that you have it on my mind, let me ask you guys.  Wouldnt you want it with a slight up elevator?  I understand that that would be a bad thing if you were in inverted flight.  Something I have yet to try.  Maybe by the end of this season I will try that on purpose 
What I am thinking is that if your plane goes into failsafe mode than some problem exists.  If it is temporary then you can regain control.  If you lose battery power then does it really matter straight and level vs slight climb?  Its just gonna fly till it runs outta fuel anyway.  Maybe the correct failsafe attitude would be a slight turn to kinda keep it in the area?  I dont know fellas, just thinking out load.