I don't think the Flynn effect is relevant for this analysis.

Speed of development (in places like India today and Eastern Europe in the early 00's), spread of English as a second language and the changing cultural standards are I think are much more important reason for the rise in number of English speaking people who use the web recreationally. Improvements in environment don't effect adult IQ much, as the nation develops and English spreads it stands to reason a previously hidden reservoir of potential users is a greater increase in numbers in absolute terms than the Flynn effect could hope to gather via children growing up with slightly higher IQs especially since many developing nations may be developing precisely because they are using up their demographic dividend.

The Flynn effect also clearly can't continue forever, there are signs that its ending or has perhaps already ended in the developed world (I think Denmark has shown a stall in the Flynn effect for more than half a decade, there may be other examples but I don't recall studies right now).