No, I haven't heard that claim.
The STAMPEDE study found a benefit among men with metastases, but they didn't break it down between high volume and low volume. In the subset of men without metastases (M0), there was no survival benefit to early docetaxel. Also, no benefit among LN+ (N1) men.
The did a secondary analysis of the GETUG-AFU15 trial. Survival increased by 20% among those with high-volume mets, although it wasn't statistically significant. Among those with low volume mets, there was a slight, non-significant decrease in survival.
www.europeanurology.com/article/S0302-2838(15)01103-3/abstract/On the other hand, it's not entirely relevant to you, but there was a trial (GETUG-12) of docetaxel (+estramustine) in untreated high risk men, some of whom had positive LNs. Those who got the chemo with the ADT did somewhat better:
www.thelancet.com/journals/lanonc/article/PIIS1470-2045(15)00011-X/abstractThere is probably some subset of low-volume met men who might benefit, but I don't think anyone knows how to pick the ones that would. Still, if you want to do it and your doctor is willing, and you understand the risks and SEs of docetaxel - that should be your decision.