I would agree that it's much cooler after the turbo.
However, the original non-flex Vishnu up-pipe had a big-ol secondary bung in it that was certainly for something larger than an EGT. I asked the guys at Vishnu what they used it for and Shiv told me it was for a wideband O2 sensor. It was about 3" from the top of the pipe.
You can kinda see it in this picture, it's got a copper crush washer on it:
Or look at this tiny, old picture. You can see the O2 bung on the outside of the bend in the top of the pipe.:
I'd prove it in person, except I've since replaced my solid up-pipe with a flex-pipe that doesn't have the bung.