DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.
Slash commands now support explicit alias definitions with the description: "Alternate names that resolve to this command (e.g., /cost and /stats both resolve to /usage)".
Evidence
Command aliases (search for "Alternate names that resolve to this command")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Related
Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.