They do, but you may have to trim one of the clamps (vertical) on the panniers.
This is due to one of the support braces on the frame interfering with the long clamp position.
It doesn't weaken the pannier or load-carrying capabilty.
The V-bracket welded to the frame below - shows the Metalmule arrangement. The MM pannier guide/clamp fits between the welds. On Touratech frame, the V is closer together, so the pannier guide/clamp needs to be trimmed by an inch.
Thanks very much for the very useful replies, I have a set of mm’s and want to use them on my GS when it’s finished and have been offered a touratec frame relatively cheap.