My opinion of claims like "LLMs need memory to manage codebases" has also hit the dumpster bin a while ago.
Why would knowing how to make a maintainable change to a codebase require any more "memory" than knowing how to play an optimal chess move? The codebase is the memory. A sufficiently capable LLM can ingest it, figure out what changes to make, and make them.
Were that the case LLMs would’ve been phenomenal code monkeys from the get go. They were not. They still are not.