I don’t see any downsides or arbitrariness of this suggestion, I mean, there are some services I will use for one month, and I intend to use it for that month, but it happened before where I would forget to cancel it, and this has happened to other users too, by default, auto-renew should be off, I don’t really know any strong arguments that can go against this point, I mean, auto-renew can be useful, but there are many cases where it could be harmful and even though people do forget it, it might be a tiny bit deceptive in some cases.
Personally I believe free trials are a great idea, and businesses should be able to offer them eithout the risk of losing actual business to it l, while at the same time I believe people should be able to make an informed decision before entering a payment (even more so to a recurring one).
This could be arranged by a simple request from the vendor that confirms you wish to pay or not when the trial ends.
To me this sounds like a perfectly reasonable requirement that doesn’t try to trick either side of the transaction.