Counter question: Why should they spend money on it? When they discontinued Flash WASM wasn't an option. Now they already have abandoned Flash, told everyone

Counter question: Why should they spend money on it? When they discontinued Flash WASM wasn't an option. Now they already have abandoned Flash, told everyone to move one and most of the monetary profitable ecosystem _did_ move on. And while there are probably still some companies willing to pay for new flash support for their legacy application it's unlikely to be worth it for Adobe. Lastly even if you could create Adobe Flash WASM it's non trivial to make it down to bug compatible with Flash. But exactly that is the kind of compatibility is what remaining legacy customers want. So IMHO it's less that they can't do it but more that for the for profit company Adobe it makes little sense.