Not really. It’s listed as an unbiased renderer, and I’m guessing it’s because we can set it up to be visually unbiased and quite mathematically unbiased (russian roulette is said to be mathematically biased but visually unbiased iirc, and is out of user control).
In practical terms, it would usually be visually biased from limited GI bounces, light threshold setting, AO hacks, MIS, light portals, caustic rays etc. Pretty much any setting we do to make it go faster will introduce slight bias, some more visual than others. Turning off caustics (without even fake compensation) is a sure way to make the image darker, because all glossy rays are terminated for lighting (everything has fresnel, right? - that’s the downside).
Considering the ridiculous amount of samples required for caustics to converge (no blur allowed I guess), using Blender in a very unbiased way, appears near impossible at least if physically plausible (fresnel -> diffuse/glossy) materials are used. I guess you could do unbiased cornell box using diffuse only materials.
So in theory, I think Blender can be very unbiased, but nobody would use it that way in practical use.