I have to give it to the vibe coding industry, I didn't think one could reinvent the wheel quicker and more often than frontend JavaScript programmers, but they're pulling it off!

I can't really tell why you would need to support the newer spec. It's mentioned that old stuff will work for at least a year after the new spec has been released, but I'm not so clear on what exactly will break. Is there some kind of phase out plan that the AI players have agreed upon for protocol versions will support for how long? Who is making these promises?

More importantly, I see a whole bunch of changes in headers and routing and whatnot on the MCP side itself, but I'm not really seeing what the advantages of the new spec are to either LLM users or MCP server resellers. Why consider upgrading in the first place?