I believe the book will be fine simply because it was supposed to be Steve Orlando's debut at Marvel. Cancelling the book would not be a good way to welcome a new talent like him.
I don't think Cassie as Stinger undermines Janet in any way, because she was clearly not set up to be a Wasp replacement the same way Hope and Nadia were. Cassie is only ever pushed as Scott's legacy or as a part of the Young Avengers, so it's not like her and Janet have to fight for the same spot.Cassie too? I never considered her as Wasp but things are planned to be that in a weird way.