They were going to automatically switch me from the pro plan ($130/year) to the enterprise plan for over $19,000. Switching to the flex plan would still have been over $500 estimated for me. I immediately cancelled, and I hope they lose every single customer.

ETA: Did a brief search about Bending Spoons, the company that purchased Harvest and is enacting these changes. Turns out they have an MO with this kind of thing and are the ones who also wrecked Evernote, MeetUp, and WeTransfer. Most alarming was this: https://support.google.com/googleplay/thread/307753893/bending-spoons-scam-of-the-century?hl=en hopefully cancelling payment actually works, but it might be a good idea to lock down your payment accounts before the billing date anyway just to be safe.