No GB is not an Apple PR benchmark. The issue, at least for Threadrippers and other similarly high core count CPUs is that GB 6 MT tests are, by design, not a good test for them. For GB 6, Primate Labs made the conscious decision that only a few of the subtests should be embarrassingly parallel (e.g. code compilation and 3D rendering/ray tracing) while the rest would be work sharing algorithms that don't scale as well. The reason they did this was to mimic how most consumer software actually behaves and to give the average consumer a better sense of the "real" performance benefit they might see from a bigger CPU as opposed to being wowed by marketing misrepresenting how much benefit they'd get out that many cores. John Poole, head of Primate Labs, stated one of the reasons he directed the team to do this was because of how upset he was of companies using GB 5 to try to upsell the average customer into getting devices they not only didn't need, but might actually be worse for them.
If you are in the market for Threadrippers or the like, then you are ... not an average consumer and GB 6 MT, beyond the scores for certain subtests, is not meant to be representative of your workloads. While Primate Labs could add a third category or a different test for "workstation MT", they seem mostly content with making a consumer-focused benchmark.