Short answer. No. Article 2252 states that changes and new provisions in the Civil Code which may prejudice or impair vested or acquired rights under the old legislation shall have no retroactive effect. A right you already validly acquired under the old law is protected from being taken away by the new Code.
What the law says
Changes made and new provisions and rules laid down by this Code which may prejudice or impair vested or acquired rights in accordance with the old legislation shall have no retroactive effect.
Civil Code, Article 2252 — Transitional Rule On Vested Rights. Read the full provision →
Your acquired right is protected against retroactive impairment
Article 2252 states the protection you are asking about in direct terms: "changes made and new provisions and rules laid down by this Code which may prejudice or impair vested or acquired rights in accordance with the old legislation shall have no retroactive effect." If you validly acquired a right while the old law was in force, the new Civil Code's provisions do not reach back to prejudice or reduce that right, even where the new Code would otherwise treat the underlying situation differently.
The key requirement: the right must actually be vested or acquired
This protection turns on whether the right in question genuinely qualifies as vested or acquired under the old legislation — meaning it had already come into concrete existence for you under the rules in force at the time, not merely an expectation or a possibility that had not yet materialized. A right that was still contingent or had not yet fully accrued under the old law would not enjoy the same protection this article provides to rights that had already become definite.
Why the law protects rights this way
Allowing a new law to freely strip away rights people already validly obtained under the law that governed them at the time would undermine the reliability of the legal system and punish people for conduct that was entirely proper when they engaged in it. This principle of non-retroactivity for vested rights reflects a broader fairness concern that runs throughout the transitional provisions governing how the new Civil Code interacts with rights and situations that existed before it took effect.
What this means for evaluating your specific situation
If you believe a right you hold is threatened by a Civil Code provision that changed the applicable rule after your right had already vested, the key question is whether your right had genuinely and fully accrued under the old law before the change took effect. If it had, Article 2252 supports the position that the new Code cannot be applied to prejudice or impair that already-acquired right, regardless of how the Code now regulates similar situations going forward.