Re the OP: I have one 2E (DS), and one gifted (DD).
Re PG: I think it's a confluence of factors.
-DYS having "lowered" stated levels for PG,
-being identified as PG in verbal OR quantitative instead of FSIQ broadens the numbers,
-increased use of the GAI where kids would have been previously been exempted from PG identification due to lower processing speeds and working memory,
-a lack of understanding or specificity in terms by users of those terms,
-increased understanding that the tail of the bell curve is bumpier than previously understood (in other words, there are more high-IQ individuals that statistical distribution would predict),
-increased media representation of gifted, and often quirky, individuals which makes it seem more common,
-increased attention in populist books on the issue (thinking Outliers and NurtureShock here, along with various newer books on achievement strategies,
the ongoing tension between anti-intellectualism and the consumerist, achievement-oriented culture wherein a gifted label confers status, and if all the kids are gifted, ones own child must be really gifted,
-the apparent declining ability of schools to offer gifted programming and differentiation, causing parents to be more dissatisfied with the educational options availalble and advocating for their gifted kids (my mom never blinked over the issue as my needs were met, while I feel like I have a part-time job advocating for my kids or homeschooling because we don't have access to other reasonable solutions).