They may mean that they're locked into continuing the subscription to keep getting updates because if you have a break then you start at the high price again.
Whenever you don't renew you get whatever version was out when you last renewed in perpetuity which is great. But if you decide you don't want it this year, but in two years you do, now you're back at the $289 price. Though if you pay $289 every other year you're still coming out ahead compared to an annual subscription so I don't know what the issue is.
first year - $289.00 (+$116)
second year - $231.00 (+$58)
third year onwards - $173.00
you're locked in because of an extra $116 the first year and $58 the second year?
https://www.jetbrains.com/store/?section=personal&billing=ye...