Once you have clicked on the link to the Greensock website, it takes exactly three single-clicks and one double-click to locate the SWC which can then be dragged and dropped into the required folder for the MMF extension.
I really think that this is a better solution for the following reasons:
1) TweenMax is a commercial product, and a link to the author's up-to-date files is best practice. Maintaining a copy of a third-party binary will lead to it becoming out-of-date. Some authors do not appreciate their binaries being accessible from third-party web sites.
2) It leaves users of the extension in no doubt that they are using a third-party, commercial product which has a licence.
Purely as a personal preference, I would rather not have to click a pop-up each time I used the extension, but I will agree that it wouldn't be a major problem.
I think that, purely as a matter of etiquette, Jack Doyle (the author of TweenMax) should be contacted. I am sure that he will be very obliging; he's an incredibly helpful guy.