Yes, the non-upgradability of RAM on MacBook Airs and later other MacBooks has been widely called out in reviews and media at the release of those models. You can easily verify that by going back to read those reviews.
That doesn't mean that it was the first, just the first that they bothered to look for that... which makes sense, because apple's hardware is generally going to be under more scrutiny than other manufacturers.
All the popular competitors to the MacBook Pro have soldered RAM including the XPS 13 and ThinkPad X1 Carbon.
Really the truth of the matter is that for 95%+ of people, RAM requirements have completed plateaued in the last 5-8 years or so.