GPS chip antenna - layout query
Yes, this can be considered a CPWG and it will do better than a line without tuned impedance.

Your dimensions seem correct for 50 ohm impedance, assuming you are using FR4 with a dielectric constant around 4.5 . The proximity to the board edge should not be a concern. 

I think you do not need quite as many fence vias. I would instead suggest to place the signal line passives straight to avoid the angle at C38, or --- as an alternative --- to use soft bends with radii around 3 times the line width.

Be sure to place C37 nearer to the LNAs supply pin and always put double vias to ground on shunt capacitors to avoid issues with via inductance.