The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
The changelog is dated May 29, 2025: "New non-Marketplace applications and new installations of existing non-Marketplace applications will be subject to the updated rate limits immediately, as of May 29, 2025."
Slack's[1][3] recap repeats the rate-limit change and says the clarified API terms "take effect immediately for new apps and on June 30, 2025 for existing apps".
Follow-up of 3 June 2025: internal customer-built apps keep their existing rate limits and are not subject to the new limits.[1]
Something missing or wrong? Say it in your own words: a link that backs this pin up, a different start or end date and why, or a fact it lacks or gets wrong. The AI checks it against this pin's sources, searches for better ones, and adds any page that backs you up. The pin's own sources still count most.