The good thing about bringing back the 17" MBP would be all the objections over battery life and low power GPUs would be moot. Even a thin 17" is going to be huge. The last one looked like 4 cafeteria trays stacked up.
I'm just not sure that there is much of a market for it. It's fun to imagine though. Mobile Xeon, ECC memory, 32 or 64 GB DDR4-2400 RAM, RAID NVMe SSDs. Priced like a Mac Pro :)
My Zbook Studio G3 is the size of my old rMBP and has a Xeon 1545m, 32GB of ECC RAM, a 950 NVMe SSD, and space for another (but m.2, not NVMe, unfortunately).
The 17" allow me to fit a dinner plate, side dish, and drink on top of it (closed), then carry it back to my desk or to the next meeting. The 15" won't fit the side dish anymore. I miss my Silicon Valley Lunch Tray.
I'm just not sure that there is much of a market for it. It's fun to imagine though. Mobile Xeon, ECC memory, 32 or 64 GB DDR4-2400 RAM, RAID NVMe SSDs. Priced like a Mac Pro :)