Insult is too strong a word. Like many here, I think something like this should be opt-in. But I also think the same about "smart recommendations" that try to auto-complete a word I'm typing or add something to my calendar based on recent emails.
I dislike them all and want them all to be opt-in. I think it's predatory by design -- but why anyone would be "insulted" is beyond me.
Opening documents in some weird "reading mode", popping up that I can pick up where I left off every time I open a PowerPoint, adding captions to my photos I add to documents (and sending my confidential data to their servers so their ML can tell me that a chart I added is a picture of a chart), "looks like you're trying to write a resume", I'll denote my three points (a), (b), and ©, how would you rate our product, etc etc.
Some people may want this stuff, I want my computer to leave me alone and let me work. MS has a pattern of disrespect to the user that overall I agree is insulting.
It wouldn't surprise me if Windows asks about product suggestions or shopping enhancements(or something along those lines) at some point and that drives this functionality.
EDIT: I don't usually use Edge so I just tried this and I received the lower price notice but not as the author describes. I got a little notice on the right side of the address bar that collapsed about 3 seconds later into the tag icon. I had to click on that icon to get the popup with the shopping details.