It pains me when people pretend to understand corporate law as it pertains to a specific issue without actually doing their research.
It pains me to see people drop terms like "corporate law" to try and sound knowledgeable when they then don't even critique, discuss or bring up a point which relates to corporate law.
Every single promise Bethesda issued regarding pre-order content contained a disclaimer to the effect of "while supplies last," which translates to "not everyone gets it."
Nope, there were definitely instances where it was said that all pre-orders would receive the map without any "while supplies last" disclaimer, such as in an interview with Todd. All a claimant would need is a copy of one of those instances.
And to respond to your previous point, lawsuits need to be over a somewhat significant sum of money. The last I checked, US law required a minimum of $20.
Lawsuits don't have to be over money at all, and as I said, "class-action."
As to your argument that people may have chosen to get a digital download as opposed to a physical copy due to pre-order promises Bethesda made: they still have no monetary grounds to sue Bethesda. Bethesda didn't make more money off of physical pre-orders than they did off digital downloads, and the businesses who would be affected had nothing to do with the pre-order maps.
In regards to the subject, it's wholly irrelevant how much money Bethesda made from what.
And you absolutely would need a lawyer. Unless you planned on spending the next year going blind on paperwork filed by an actual legal team that can actually read the (very much not black-and-white) laws regarding false advertising.
Funny, I didn't need one and I successfully sued. I guess you just don't know what you're talking about. Go figure.