This massively affects my playtesting. During the F&F playtest, I playtested with roughly three groups, for a total of maybe 15 players, all of whom had signed the NDAs. Out of those groups, two, with a total of roughly 10 or 12 players, were entirely or mostly Skype based. Those were the groups that I expected to participate in the open playtest with. (Ironically, the face-to-face group has mostly dissolved because of the end of the school year.) Without the FAQ interpretation, I would expect to play heavily using the playtest rules.
Assuming that the FAQ is incorporated into the agreement (not obvious to me) and that the prohibition is intended to include private playtest groups, not just to prohibit posting a general invitation to playtest D&D Next on Google Hangout or whatever, this rule will essentially eliminate my participation in the playtest, along with the participation of roughly a dozen other active playtesters who provided extensive feedback.
(As an additional aside, it makes sense to test D&D in all of the ways that D&D is played. And today, one of the major ways in which D&D is played is via Skype, virtual tabletops, Google Hangouts, and other forms of communication.)