That really depends on how much inflammation is present before the SRP. If the gum tissue becomes less inflamed then the gingiva will tighten with the possibility that the gum line will be lower.This is not a result of actual SRP but the inflammation that is present.
If you have gingivitis then yes i could lead to a "lower gumline". Keep in mind that the gums are swollen and therefore when they become healthy again they will be lower.