Unstoppable Wasp was brought back as an ongoing, and so far has 10 issues solicited. It just isn't on March's list as issue 6 got delayed to the start of April. It's sales have unfortunately been as low as Squirrel Girl's.
Champions sales actually seem to be improving. February's orders were for 18,953 copies - so March's issue sold around 600 more! And December's only sold 18,199 (January's would be an unfair comparison, being an issue 1).