Isn't it good for the mixer? This should add extra credibility for the mixer , using a reliable service to take care of the mixing.
I guess, it's good for the mixer but I believe Thormixer don't want to state their links with Jambler and wants to perform their operations as an independent mixing platform. I believe they've already got enough good users who use their platform and that's why including any relations with Jambler isn't a priority for them.
And thinking from the other angle, we can all agree that the mixing business In crypto today have become a very competitive one, and a mixer publicly associating itself with a bigger mixing platform, could also lead to the mixer losing some of her clients to bigger mixing platform they associated with.
People like to experiment and compare, and let's assume that jambler is the platform that powers Thormixer and several other mixers around, this means that part of the fees client pay to Thormixer goes to jambler, if this be the case, there is no need for Thormixer to put jambler forward as that could mean promoting jambler to her(Thormixer) clients when she(Thormixer) is still looking for more clients.
Just my thought, could be wrong.