According to the company (via VG247), they are predicting that Destiny 2 will be able to ship as many as 3 million units within the first 3 months of the game’s release alone. Note that this prediction is just for the PC only, where Destiny 2 will be the first title in the series to be made available on the PC.
In addition they are predicting that total digital sales will be between 4-5 million units. Given Bungie’s reputation, especially for the Halo series, many are expecting the Destiny franchise to be a huge one. The game is currently set for a release in September where it will be initially released on consoles first, and it is expected to be launched on the PC in October.
The open betas will be kicking off next week for console gamers. Those who pre-ordered the game will also be granted early access to the beta. The PC beta is currently scheduled for August, so PC gamers will have to wait a bit longer before they get their hand son it.