$7000 preamp vs $700 receiver - Is the difference THAT significant?

You said: ignore the multichannel but you have an AVR in there. What exactly is its function?
The AVR is a poor source and a poor preamp / amp. You don’t even have the top of the line which is somewhat better. You also have a underwhelming source (Bluesound). 
To hit both on the head you should indeed look for a multichannel pre/pro. The 8805 would be a good place to start. But you are stuck with Audyssey. Better still - a NAD M17. You draw two benefits from the NAD: you stay in the Bluesound ecosystem (V2 comes with a pretty decent streamer so you can forget about the separate box) and you get Dirac. You will further benefit from the balanced outputs, if your stereo supports them. 
The NAD will give you a flavour of what good stereo sounds like. You’re not quite there yet but will get you a bit closer. 

And why do you need Tidal MQA? I have a pretty decent DAC. And I prefer Qobuz for sound quality. 

Yes it is... But I would not buy McIntosh. There are better preamplifiers on the market in 7.000$ price tag. You may want to check Ear Yoshino 912 or Atma Sphere MP-3.

This thread has probably long since been exhausted...but has anyone here spoken about receivers made by Outlaw Audio? Curious how those might compare to the others mentioned. I’ve heard nothing but great things in terms of SQ.

I appreciate everyone’s input. It’s great to get such a wide swath of opinion, and that's exactly what I expected.

This question/exercise was to help me with the "premium vs consumer" argument, leaving brands and all else aside.

Granted my equation will have some external influences (Love those blue meters) (Have an uncle that has had blue meters since the 70’s) etc... but hearing that "you will notice a difference", is what I was hoping to resolve here.

Not everyone’s system is perfect. Not everyone’s listening environment is perfect. But ceteris paribus, this is a good improvement to make.

Thanks all!