Just as a reference, I am on a shared 1 gig data plan for all three of my devices. These devices are used for work, with the iPads doing multiple forms from the cloud throughout the day on my busier days.
Has my data usage increased? Not enough to kick me into the next highest plan. in fact, I still have a comfortable margin to go. How do I do that? By limiting high-bandwidth activities to times when I KNOW that I have a good Wi-Fi signal. Due to the construction of my residence, there are certain areas that have a low cellular signal. By the logic of this lawsuit, if by some chance I was saddled with an ISP which instituted data caps on my home network, I should be able to sue over the voice call over Wi-Fi feature since it would increase my data usage on my home network.
The setting to turn the Wi-Fi assist off is only slightly misplaced IMHO - it actually should be above the "Use Cellular Data for" apps list, right below the "Cellular Data Usage" counter. Thats a more appropriate place.
In that same screen is a setting to determine what you want to allow to roam. For my iPhone, I can control voice, data, and international CDMA.
IMHO this is no different than the roaming settings - if you have reasonable suspicion that you would have an issue, the intelligent thing to do is either look for yourself or ask for help before it becomes an issue OR the first time you experience an issue.
While there have been a couple of well documented posts in the thread that showed actual issues due to their unique circumstances, I believe the most common issues with the new wi-fi switching algorithm are part of a larger trend; it is more of a failure of industry in general to provide clear, easy to read, written on paper guide to the capabilities of todays electronic devices. Despite the efficiency of electronic documentation, it is human nature to click through it or ignore the links. As an example of how this works, I just got a new van for work. The info center has a few features that can be programmed that I never knew about, until I opened the owners manual. If it had been a CD book or a download, I wouldn't have bothered, and would have missed a few things that make my life easier. An Apple manual in type that doesn't require a magnifying glass, one that at least covers the Settings area in a general fashion, saying what kind of settings are where, in a paper form is the most likely way to get users to actually become familiar with those areas.
As far as the legitimacy of the CA: A perfectly reasonable CA was the Ford Pinto lawsuit, where an engineering change by Ford made the vehicle a rolling death trap. By the same logic used in this CA, we should also be able to sue Microsoft for the Windows 10 updates they now force you to download, not giving you a way out of it. This type of lawsuit is what drives up costs on everything. Any time a new material is developed for something, they now have to factor in the cost of someone finding out a previously unnoticed side effect of being near it and filing a billion dollar CA suit. (Asbestos anyone??) Medically, besides (I've been told) almost half the cost of your doctor's visit going to malpractice insurance just in case they miss something and get sued, (I lost a nephew to an intestinal rupture - we didn't sue the doctors for not finding the weak spot he had from birth!), but if a medicine has a side effect that was not found during testing the lawyers are all over it, and instead of resources going to finding a better medicine they go into finding a new yacht for some lawyer.
In the situations that have been mentioned, the poster noted that they had located the setting, even if it required some research, and turned it off. The question that needs answered is what percentage of the user base is experiencing similar issues? The only unbiased source I can think of is the cell providers; if they reported actual numbers of people with this issue then we could go to Apple with something that they can use. Otherwise, assumptions must be made, and those never work out.
Case in point: Let's assume only 50 percent of iPhone / iPad users post on the net, no matter if their experience is good or bad. to keep the numbers reasonable, I'll focus on the users who bought a 6S and 6S Plus in the first week, which was reported as 13 million (rounded) that gives us 6.5 million posting about their experience. Let's say only 10 percent of those actually go to Apple or forums like this to get news. we are down to 650,000. A serious flaw would be roughly a 10 percent problem rate, so you would see 65,000 people posting their issue. A Marginal problem that should be considered would be a 5 percent rate, or 32,500. Now to throw a monkey wrench into the works, it is a safe bet that 1 percent of all of the posts (at least on sites that do not monitor their users) are from people who have nothing better to do than to complain about a product they don't even own. I didn't notice any one percenters in this thread, but in other websites they run rampant at times. The theoretical question with these numbers is do we have somewhere between 30,000 and 60,000 of the users in this sample group having the issue? If the answer is yes, then a bug exists; if it is higher then it is broken, if it is lower than there are some unique situations that exist that we need to look into further. Any change in a product from any company, not just Apple, goes through that kind of review when problems are reported.
Sorry for the book, but I just couldn't stop until I made my points!
