To put any doubt to rest here are the tech specs from Apple for the 2011 17 and 15 inch models. There was one 17" stock configuration at $2,499 and two 15" models, a $2,199 variant which was specced exactly the same as the 17" pro, and a cheaper $1,799 model which had lesser specs.
https://support.apple.com/kb/SP621?locale=en_GB
https://support.apple.com/kb/SP620?locale=en_GB
Overall with the 15" having much more pricing flexibility and still being considerably cheaper for the same power, it's not difficult to see why the 17" found itself limited to the niche of people who specifically wanted a larger screen. This is probably what led to it's downfall via lacklustre sales. By the time it came to 2012, with retina being the new flagship feature, they’d have probably needed a retina 4K (1920x1200 @2x) because the 15” retina can already display 1680x1050 adequately (which brings us back to the whole what’s the point of paying so much more for the 17” question).
A bit of an assumption here, but if we take the current 4K iMac as an example, it seems they can’t run it ok even given modern day integrated graphics (I assume even more than cost why the lowest end is non retina). For a desktop with a discrete GPU not really an issue, but at least a bit of an issue for a mobile computer back in 2011, even if it’s a desktop replacement that will be plugged in much of the time.
So to finally bring this back to OP's question, if they
do ever make a 17" again, I would really expect it to be a sort of super halo product like the iMac pro. Probably starting at at least $3,999 quite possibly even more than that. All enterprise grade components (hence the cost) which will likely be great for many, but if your planned use is anything other than work related 3D modelling, video, coding, etc (pretty much anything you'd also consider an iMac pro for) it would likely be extremely difficult to justify for anything else.