Retire wording tied to pre-2.0 milestones

[maxisbey]

Several docstrings, comments, and story READMEs still describe work as "expected before v2 is final", "planned before beta", or "revisit before beta" — milestones that passed when 2.0 shipped.

Motivation and Context

The provisional middleware/dispatcher surface stays provisional, but the caveat now says what it means going forward — "may change in a 2.x minor release" — instead of pointing at a milestone in the past. The stale beta TODOs on the stories are dropped, and the middleware story is corrected: it claimed MCPServer has no public middleware accessor yet, but MCPServer.middleware (and the middleware= constructor argument) shipped in #3201.

How Has This Been Tested?

Wording only. ruff and pyright clean via pre-commit.

Breaking Changes

None.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

Two adjacent notes were left alone on purpose: stories/error_handling ("the contract is under design") and stories/README.md ("hosting surface that are still moving") — neither names a milestone, and whether they still hold is a separate call.

_{AI Disclaimer}

[github-actions]

📚 Documentation preview

Preview	https://pr-3211.mcp-python-docs.pages.dev
Deployment	https://9a99f14c.mcp-python-docs.pages.dev
Commit	4bf4934
Triggered by	@maxisbey
Updated	2026-07-29 13:50:27 UTC

[cubic-dev-ai]

No issues found across 14 files

_{Re-trigger cubic}

[claude]

LGTM — wording-only change retiring stale pre-2.0 milestone language; no behavioral changes.

What was reviewed:

• Confirmed every hunk touches only comments, docstrings, README prose, or a divergence-note string in test metadata (tests/interaction/_requirements.py) — no executable code changes.
• Verified the middleware-story correction against the source: MCPServer.middleware and the middleware= constructor kwarg do exist in src/mcp/server/mcpserver/server.py, so the old "no public accessor yet" claim was indeed stale.
• Checked the new "may change in a 2.x minor release" caveat is applied consistently across the middleware doc, both server docstrings, and the dispatcher protocol.

Extended reasoning...

Overview

This PR updates wording in 14 files — docs (docs/advanced/middleware.md), story READMEs and one story module docstring under examples/stories/, code comments/docstrings in src/mcp/server/lowlevel/server.py, src/mcp/server/mcpserver/server.py, and src/mcp/shared/dispatcher.py, and one description string in tests/interaction/_requirements.py. All changes replace milestone-relative language ("before beta", "before v2 is final", "before v2 stable") with forward-looking phrasing ("may change in a 2.x minor release") or plain statements of the current state, now that 2.0 has shipped.

Security risks

None. No executable code paths are modified — the diff consists entirely of comments, docstrings, markdown prose, and a string literal inside test requirement metadata.

Level of scrutiny

Low. The only substantive claim requiring verification was the middleware-story correction — that MCPServer now exposes middleware publicly. I confirmed both the middleware= constructor parameter and the middleware property exist in src/mcp/server/mcpserver/server.py, matching the PR description's reference to #3201. The _requirements.py edit changes a divergence note (documentation embedded in test data), not any assertion or test behavior.

Other factors

The bug hunting system found no issues. The PR is consistent with the repo's own AGENTS.md branching-model guidance (main is the stable v2 line), the author deliberately scoped out two adjacent notes that don't name milestones, and the remaining provisional caveats keep their intent — they just no longer point at a milestone in the past. No prior reviewer comments are outstanding.