Right, but they weren't making money on that either, only $5k/yr. This wouldn't happen to a "top arr client" or whatever is the tiering their account managers follow.

Here it likely was the exact opposite: the long tail of low-paying clients is annoying to manage compared to how much they bring cumulatively. So the client had been given a choice of either becoming a high-paying client or stop being a client altogether.

That could be done so that it doesn't look like extortion though

Absolutely, it's just there's no commercial pressure on Salesforce company structure to evolve towards valuing the feelings of small clients.