Bit perfect in reference to the files that are being downloaded from the service provider server. What else could we be asking? Fortunately we know our CD rips are bit perfect, I hope we can expect the same in streaming.
People have short memory. During many years, CD players were rated by their error correction capability - "experts" used the Pierre Verany Digital test CD - I still own it - filled with all kind of imperfections, and the best were just the transports that managed to track better the challenging tracks - they were supposed to be more "bit exact" - at that time we said they had less bit errors. Only much later it was found that even average CD reading mechanisms had a minimal number or no errors in real playback and the famous torture tracks were omitted from review measurements, that focused on jitter and subjective aspects of sound quality.
If we can't be sure that we are getting the "proper" bits and consumers and reviewers do not have access to tools to know the situation, I would really say "Houston, we have a problem". We have still a lot to learn until we can trust in streaming.