tsc already has incremental mode, also there's the LSP, the bundler in watch mode could keep a persistent TS language server running. if the typecheck succeeds the bundler emits the new bundle, easy peasy.
If I remember correctly gulp(js) was perfectly able to do this.
but how do you do it? this is not as easy as it may seem. Of course it's possible but the value here is that I don't have to do this for every IDE and/or the LSP when I use webpack where waiting on the typecheck is an integrated feature.
I don't think that's an integrated feature of Webpack, though. It is a feature of TypeScript's own compiler (`tsc`), but that's about it. Nothing about Webpack supports typechecking (or TypeScript) natively.
If I remember correctly gulp(js) was perfectly able to do this.