cannot complete the Guti Evo as the EVO arena is not there anymore.

This is all I got from them on live chat:

"I see some other players have reported the issue on forums and let me help you to get this reported for you as well."

So get ready for Evo Arena to come back one day before Great Guti ends I guess... How they overlooked the fact that the friendly ends before the evolution does is beyond me. No quality control whatsoever.