There is no pin unless the g5 Knight is an undercover Bishop.
Your e6 bishop is not "unsafe" given that Nxe6 fxe6 regains material if you are a fan of the "B = N = 3 pawns" math.
Though Black seems willing to lose his bishop pair (which can be valuable given the right circumstances) in exchange for developing another piece and preparing to castle.
A move like Bd7/Bc8 moves the same piece twice in the opening without a really good reason to do so, so that's more of a general principle violation.
In summary, it looks like Fritz (at whatever level you are playing at) made this trade-off decision though I do find it odd that the computer undervalues having the pair of bishops (which can sometimes be worth half a pawn when your opponent does NOT have the bishop pair anymore plus you actually know HOW to use a pair of bishops :))
Another explanation is that learning chess from computer moves is probably a horrible idea to begin with if you are just starting out . :)
This is from a game I played yesterday. I'm doing an infinite analyses of some of the positions and normally I do understand the moves that Fritz is coming up with.
However in the below position, black to move, Fritz is best is Be7.
I don't really see why this is the best move for black. Isn't it better to get his e6 bishop to safety?
The only reason I can see is that it frees his queen from a pin and he can start moving his knight on g5 but it seems strange that this would justify the bishop on e6