It seems that PC users won’t be able to enjoy Rock Band 4 on their PC rigs, since Harmonix’s crowdfunding campaign fell well short of the $1,500,000 the developer was aiming for. To be more exact about the figure, the campaign was concluded with $792,817 spread across 1,674 backers.
Harmonix was intending to add an additional $500,000 into the development of the port after reaching their initial goal, but now it seems that this scenario will probably never happen. Sumo Digital was intended to handle the PC port of Rock Band 4.
Now we will have to wait for Harmonix’s promised post-campaign update that will probably include the official announcement regarding the port and its cancellation. You never know what might happen, but it’s rather unlikely to see a PC version of Rock Band 4 after the failure of the campaign.