Has the meltano team considered upgrading their slack subscription or moving to an open source alternative like mattermost (FOSS slack clone)? With slack's free plan we can only have messages from the last 90 days and everything older gets auto deleted, and that's not ideal imho since there's so much troubleshooting advise that gets lost. We had a similar problem in a company I worked for and we switched to mattermost to not have to pay the exorbitant slack fees and still keep our older messages.

https://discuss.meltano.com/ syncs this workspace