My best guess is that phoenix hasn’t quite caught up with this change. It’s just a deprecation, so I would assume you can ignore it and that it will most likely be fixed in the next Phoenix version.
Thank you , I figured it was OK but it’s not what you expect to see on a freshly minted project, starting out with compiler warnings before you even write a line of your won code but given the amount of behind-the-scenes code dependencies it’s too be expected from time to time I guess.