From original question it is unclear the type of Schedule adopted by OP.
There is no automatic input detection and update for schedules. But, nonetheless I would suggest adoption of Connecting Builds.
In connecting build you mark the following types:
Inputs are only providing data, Trigger are physically deciding the build' starting condition (you can configure Input + Trigger on any desired RID).
All intermediate datasets will be automatically marked as "Will attempt to build", hence automatically triggered in the flow.
Since there, you have "only" the burden of updating the schedule in order to identify the triggering datasets whenever you modify your codebase.