Interesting. I just checked through a few of my guns to see if any did this. Only one - my newest Gen4G17 - had any wiggle. G4 G35 and G3 G17RTF were both solid. I only just got the G4G17 recently and I definitely was having a harder time with it than I was with my 35, but accuracy was more or less on par (or better) than my Gen3G17 that has no wiggle.
More concerning is that this G4G17 seems to be shooting more to the left than the rest of my glocks (i.e. I am thinking it's not me). I keep looking at the muzzle and it seems like it is possible that either the front sight hole is off center or the bore itself is off center, but part of it might be just me looking at it for long enough to go crosseyed...
I'll give it a good shake out next time I hit the range.