From GameWatcher: “Key reseller G2A’s proposed key blocking tool hasn’t proven all that popular among developers. Only 19 studios expressed their interest in using it with three days left before the first deadline.
G2A had previously stated that it would cover all the costs of development for a key blocking tool as long as at least 100 developers signed up to use it.”
Source: N4G PC G2A's Key Blocking Tool Not Popular Among Developers