Information retrieval (IR) benchmarks typically follow the Cranfield paradigm, relying on static and predefined corpora. However, temporal changes in technical corpora, such as API deprecations and code reorganizations, can render existing benchmarks stale. In our work, we investigate how temporal corpus drift affects FreshStack, a retrieval benchmark focused on technical domains. We examine two independent corpus snapshots of FreshStack from October 2024 and October 2025 to answer queries about LangChain. Our analysis shows that all but one query posed in 2024 remains fully supported by the 2025 corpus, as relevant documents *migrate* from LangChain to competitor repositories, such as LlamaIndex. Next, we compare the accuracy of retrieval models on both snapshots and observe only minor shifts in model rankings, with overall strong correlation of up to 0.978 Kendall 𝜏 at Recall@50. These results suggest that retrieval benchmarks for technical documentation, e.g., LangChain, can remain reliable when re-judged in the drift regime we observe, where relevant evidence is *relocated* rather than invalidated. All resources (code and data) are publicly available at https://github.com/fresh-stack/driftbench.