I don't think this is right at all. The attack first created 100,000 wETH ($320 million) on the Solana side, and then bridged 93,750 wETH ($250 million) to ETH on the Ethereum side [1]. So some of the added ETH backs the remaining 6250 "extra" wETH tokens on the Solana side, but almost all of it would have gone to replace the stolen 93,750 ETH, and that's a pure loss. Either way I don't think this would cause any inflation, since the wETH still corresponds 1:1 with locked ETH.