They talked about it on the AMA. I made a huge summary with all the answers, here’s the link to it: Summary of the AMA on March 6, 2019
Just read it and see they say in some answers what things will come with the new season/next update.
They said they would slow things down, 2 months is pretty okay without a new hero. They did some amazing reworks and are doing this huge update now. They can focus on new heroes later this year.