Let the food do the talking. If it’s authentic, it’s authentic. The informed food cognoscenti can discern for themselves what is good and what is proper cuisine - even if a so-called “ethnic” cuisine is cooked by a chef who is not of that race or national origin. “Foodies,” on the other hand, often fall for certain buzzwords. In part, savvy marketers leverage the cachet of these buzzwords, but perhaps there’s a less commercial explanation, too: the food media (which, btw, is for the most part rather hackneyed) continues to rehash information and promote fodder to foodies’ expectations by repeating these buzzwords. A chef’s pedigree is a salient detail because there’s a correlation, but not necessarily a causal relationship, between a chef’s pedigree and his/her ability to cook good food. The question becomes to what extent the chef’s pedigree will translate to successful cooking of food belonging to an ethnicity or culture that isn’t originally theirs.
But for people being able to really try the food and have an informed perspective to evaluate it, we are left to rely on whatever information we have from food media or word of mouth. When one is trying to decide on where to eat when there’s 50+ options of the same cuisine, heuristics would tell him/her that such pedigree or background is a good starting point to narrow down the field of what might be good.
Can a non-Japanese chef make good Japanese food? Sure, as long as he/she understands the cuisine and the principles underlying it. Why there’s a greater chance of a Japanese chef making proper Japanese food, however, is that the Japanese chef should have naturally been steeped in Japanese culture and therefore have a good understanding of the elements that make particular Japanese dishes good. Take, for example, dashi - many non-Japanese chefs get this wrong, even high-end places like Manresa don’t quite get this, imo. On the other hand, some of the best sashimi I’ve had was at Saison - not just in terms of quality, but in how the texture and flavor demonstrated they knew exactly what they were doing with a Japanese-inspired dish, even if the food isn’t Japanese.
Ultimately, it depends on each individual chef and/or restaurant, as well as the cuisine a chef is trying to tackle. Blanket statements about whether a restaurant with “ethnic” cuisine will be good or not based on the pedigree of a chef are useless.
My take has always been to find people who demonstrate tastes similar to yours and/or who have a very good understanding of what makes a particular cuisine good. Follow them, and largely ignore food media, San Pellegrino lists, blogs, etc. I partly blame people like Bauer, who seem to often be uninformed about good “ethnic” food. You can tell by not only the restaurants they choose, but also by what they choose to focus on when they write a review.