I've never understood monthly subscriptions. It's not like it's technically difficult to implement prorating or even look back and see that I haven't used Disney Plus at all and refund me for non-usage.
This event probably triggered a lot of their inactive subscribers like me to look at their bills. Not only will it lose a lot of these people but the required marketing efforts to bring me back would cost a lot more now too.
Has nothing to do with ease of implementation. Has everything to do with the bottom line. Not refunding the remaining half of the month, not refunding the previous unused three months - this keeps money in the corporate bank.
Nothing that involves time and/or money is easy to implement. Not (only) because the code would be hard to write, but because what is at stake. Also, letting money flow back to the customer can lead easily to money laundering/legal problems. So, maybe it is not "technically difficult", but it sure costs more money to make it possible, than other things.
While it will give a little more revenue, I suspect keeping users longer in a "self-paid trial" might ended up change their mind and keep the subscription.
The only reason I would subscribe would be an interesting movie/tv show that I cannot find anywhere else. Frankly, these days if I find those, they just go onto my backlog... then there are also my games, books, bucket list things to do backlogs. So, I'm not subscribed to anything.
This event probably triggered a lot of their inactive subscribers like me to look at their bills. Not only will it lose a lot of these people but the required marketing efforts to bring me back would cost a lot more now too.