With the announcement of EA Play coming to Xbox Game Pass for PC (and Xbox Game Pass Ultimate) it seems the beta period for the PC subscription is now really over. The $5 introductory price will be replaced by a $10 price from September 17th onwards. A snippet from the Xbox Wire article:
And we’re continuing to add great games and experiences to Xbox Game Pass for PC. Game Pass for PC and the Xbox App will become generally available on September 17.
If you’re currently subscribed to Xbox Game Pass you’ll be paying your current subscription fee untill the next billing cycle.