Nothing wrong there, that's how VW/Audi designed it. The engine can work within a specific temperature range. So owners don't get worried with a constant moving temp gauge they fixed it at 90c when it's within this design range. So for it to move to 95c is odd. Worth keeping a check on but could be down to the recent hot spell.

Experienced as I am in driving my car in 40°+ temperatures, I can say that the temp gauge on the S8 will rise very slightly above the 90 mark on extremely hot days (35°+), but only in traffic or at low speeds.
Moving at good pace, the speed settles and stays on 90°, even at 42° (the highest temperature I've driven in since owning the S8 - some mild summers recently :p).

With the climate control on automatic (ie. Aircon on), the aux fan runs at slow speed constantly (nearly inaudible). It will turn off on Econ mode and then run purely on temp settings.
The trinary switch will of course trigger higher fan speeds as the engine temperature rises, which may be the 'trigger' David is hearing at 94°.
Different markets may trigger this differently of course, though I don't see why they'd bother when you could potentially drive it to a hotter climate...

Thanks all for your input.

I'll definitely keep an eye on it and report back if anything changes. I may look to change the coolant temp switch as a precaution too.

Lol, I did say use a pen :)
Yes I agree not necessarily the best test, I read it on the internet.

I'm going to check my fan and report back.