Does it matter if it is out of the training data? The models integrate web search quite well. What if they have an internal corpus of new and curated knowledge

Does it matter if it is out of the training data? The models integrate web search quite well. What if they have an internal corpus of new and curated knowledge that is constantly updated by humans and accessed in a similar manner? It could be active even if web search is turned off. They would surely add the latest Euler problems with solutions in order to show off in benchmarks.