I think they actually are in the 1%. You only need 400K a year to qualify. Between Frank's basic salary of 260K and grants of stock he seems to be getting, I'm pretty sure they get over the line. Frank sold 360K of Wave Life Sciences stock last year, and another 130K before May this year, and he still apparently has over 500K worth of it left. Even though the value of the stock is decreasing, he still seems to have a significant amount left. I suppose these could well have been options he couldn't exercise until they vested I guess, so there might an offset to this income, but if he's exercising the options at all then he's certainly making some profit on the deal.
They may not be "mansion in the Hollywood hills" rich, but they're way up there vs. the average household. It's just they spend all their money on stupid crap like BriBri's various "business" endeavours, her Porsches and her useless political staff.