The answer is "probably", as the steels won't have as convoluted a shape at the rear of the wheel as a cast alloy one, but in all honest you'll not know for sure that the GTI calipers clear until you fitted one. I think it's far more likely than not, the ET being only 1mm more than the standard 39mm of the 17" Oswalds, and as a worst resort, a thin spacer should be all that would be needed to clear any foul condition.
I use 15" original Tsi wheels as winters on my Gti, and all the front needed to clear was a 2mm spacer, However, 16" OE Triangle" Up alloys, and 16" "Upsilon" alloys still need a similar spacer, so it's all to do with the shape of the back of the wheel, rather than diameter.