For most users it isn't a bad deal at all. It's a 33% price savings over straight monthly, and I suspect many/most users have subscriptions much longer than a year.

This all seems a bit overwrought. Like the root post, I cannot fathom who would go through a purchase process that included the phrase "Annual plan, billed monthly" and not clue in. Or that that drop down includes a separate straight monthly plan at a significant price premium (50% higher). To give even more of a hint, a separate "you have until this date to cancel without a penalty" disclaimer gives another clue.

On the scale of dark patterns, this one is pretty eh. It clearly could be clearer for people who seem to just click straight through stuff, but I suspect a lot of the people chose the cheaper per month annual plan thinking they were hacking the system, and then discovered that it wasn't all upside.