I'm not aware of a measure that does exactly this, however there is one that replaces exterior windows that could serve as starting point for a measure to replace construction sets.
Another solution for you is to use the Space Type and Construction Set wizard measure. If you just want ASHRAE 90.1 construction sets vs. your own custom construction sets then this may work. You can set true/false argument to make or not make both space types and construction sets. This is intended for models that don't yet have constructions, but it should work on models that do have constructions if they are all set through a building level default construction set, vs. hard assigned constructions or construction sets assigned to space types, building stories, or individual spaces.
We will have a version of this measure online soon that uses the openstudio-standards gem that will included 90.1 2013.
Update:
@Matt Koch, you were really close with your initial code. I just had to change how you get the variable here
https://github.com/UnmetHours/openstu...
And then once you get the variable you need a .get
to get the optional object, then you need to cast it to the right object type with to_DefaultConstructionSet.get
https://github.com/UnmetHours/openstu...
I posted the measure so others can enhance this or use it as a guide for similar measures that alter other objects. It might be nice to add bool argument to remove any other constructions assigned deeper than the building level (BuildingStory, SpaceType, or Space). There is already another measure you could use to remove hard assigned constructions.