Yes that would be interesting. What would a representative number of dinner guests be?

But it might be that people actually find ethical meat generally tastier when presented as ethical meat i.e. placebo. (I do understand that the study you suggest would be blinded).

My main message though was to draw attention to the halo effect in diet and medicine, I have encountered people for example that take for granted that antibiotic-resistant bacteria are generally stronger than it's non-antibiotic-resistant counterpart.