Correct. I'm not sure why you'd think the migration would be exaggerated; what implicit motivation would those exaggerators have? By contrast, some people who talk about the success of, say, the 3DS might blow it out of proportion, because they're big fans of Nintendo or of the 3DS in particular and are motivated to make its success seem bigger than it is. There are a lot of Playstation fans who hang on every scrap of success the Vita or PS4 have in Japan, as well.
There are so few mobile fans on GAF, however, that virtually no one is motivated to exaggerate mobile's success. If anything, there are a good number of traditional Japanese game fans who earnestly wish this transition wasn't happening and would be motivated to downplay the success of mobile platforms.