Maybe I'm not getting it but you're on a free plan, which only gives you 90d of history, but Slack has been keeping all your history, which you can't access but

Maybe I'm not getting it but you're on a free plan, which only gives you 90d of history, but Slack has been keeping all your history, which you can't access but you have an issue with them deleting >1yr old history? I'm pretty sure they've kept this history as an incentive for people to pay so they can gain access to it. Now they've decided the costs of maintaining history >1yr are larger than the value they get from maintaining it. If being able to have this history is important enough to you then I guess you'll want to be on a paid plan. Slack doesn't provide a free plan out of the goodness of their heart, they provide it to get people to eventually become paying customers. It's a business.