I wanted to share a blog post I wrote that explains some ways to migrate chat history from platforms such as hipchat, slack, etc. into Microsoft Teams. The post is specifically for Hipchat, but will most likely work for any chat platform that has an export feature with some tweaking.
According to the uservoice website (post written today), it still looks like an official migration into Teams from a different platform is still far off.
My methods are a little hacky and will require some development experience with access to tools such as Visual Studio but wanted to put it out there so hopefully people with similar needs can see that ways do exist and we can improve on it.
I expect migration story around teams will change when we have the API ready to perform this...not so sure if Microsoft will provide tools to migrate from other platforms to teams. I would expect or course that third party companies will provide this support