Please include a 'Programmer Art' style resource pack in your next update that reverts all the textures back.

Was always planned, even if you have to download it separately. If you check your version, it's an alpha, probably the one phantom asked for, and it's still very much a work in progress

I will also note that not everything has an old texture, so this will only apply to the things that do have an old texture

That's reasonable, you can't expect newly-added things to be reskinned.