>>14276850it can't; all remaining Atlases are spoken for. Only their competitor SpaceX has spare launch capacity. ESA is similarly fucked, with Soyuz shut down and Vega requiring some Ukranian electronics in the upper stage.
I think only India could possibly put some up, but they are also having problems due to COVID, floods, and a switchover of manufacturing to the private sector.
This was extraordinarily bad timing for OneWeb, with many launchers about to retire, and new ones not ready yet (Vulcan, Ariane 6).