We really do need to move on from the WWC. This is only going to get worse. I don't like the "economically moderate" suburbanites we're getting in exchange but our base of urban voters and minorities is progressive enough to keep the ball rolling on Medicare For All, ect.
There's zero evidence these suburbanites are actually "economically moderate". That's just media framing and incorrect perception. Studies have shown Romney-Clinton voters to be more liberal on economics than Obama-Trump voters, with far less racial resentment.
In any case, we saw candidates that weren't hiding being progressive like Stacey Abrams and Beto O'Rourke do really well in those "moderate suburbs." Both of them made big gains on even Hillary's gains in those areas.