Update docs/src/v14_migration_guide.md

Co-authored-by: Sam Isaacson <[email protected]>

Author: TorkelE

docs/src/v14_migration_guide.md

@@ -11,7 +11,7 @@ In ModelingToolkit v9 (and thus also Catalyst v14) all systems (e.g. `ReactionSy
 - Only incomplete systems can be [composed with other systems to form hierarchical models](@ref compositional_modeling).
 
 A model's completeness depends on how it was created:
-- Models created programmatically (using the `ReactionSystem` constructor) are *incomplete*.
+- Models created programmatically (using the `ReactionSystem` constructor) are *not marked as complete* by default.
 - Models created using the `@reaction_network` DSL are *complete*.
 - To create *incomplete models using the DSL*, use the `@network_component` macro (in all other aspects identical to `@reaction_network`).
 - Models generated through the `compose` and `extend` functions are *incomplete*.