I recently replaced the steering shock and two tie rod ends on my '89 300E. I was told that none of this would require alignment but there was a noticable pull in the steering after.....
I suspect it was the tie rod ends that made this necessary but not sure. There is no reason the shock should change anything.
If I was putting 4 new tires on though, I would be tempted to do an alignment uness I was very sure the car didn't need one.