For what it's worth, I'm a firm believer in the follow-up. I know it seems like follow-ups always result in rejections, but that's because most submissions result in rejections. They engaged with you when they asked to see your manuscript, so you deserve an answer. It's a professional courtesy, and far too many agents and/or publishers are allowed to get away with never responding to their requests.
...which McBride attributes to firing an "unresponsive" and "pretty damaging" accountant, losing the company's counsel (whose husband died), and "substantial growing pains, mostly in the past 6-9 months," that went along with their "amazing growth."
"If you owed [sic] a payment of any kind (advance or royalties), I will be in touch regarding when you or your agent or attorney as to when you will be paid."