Is there any way to generate the d.ts-files from the original gsap files? I assume .from was missing because the file has been written manually somehow.
Ref documentation found at http://greensock.com/docs/#/HTML5/GSAP/TweenMax/staggerTo/
An array of target objects whose properties should be affected, or selector text that gets passed to TweenLite.selector (for selecting DOM elements). For example, if jQuery (or similar) is loaded and you pass ".myClass", it would act as though you passed in an array of DOM elements that had the "myClass" class applied. The same behavior applies if you pass a jQuery object containing multiple elements (like $(".myClass")).