Some parts of iMac Pro , Mini , and MBP 15" probably do greatly foreshadow what the new system will have. 4 Thunderbolt ports; probably yes. The MacBook corner case aside, Apple hasn't wavered in commitment to Thunderbolt and TBv3 with the last several rounds of updates. A T2 (or T-series); probably yes. (it is on the new MBA also). Apple wanting to be a visiable player in security and privacy is a drum that the company as a whole is banging on loudly. The Mac Pro probably isn't going to be an 'except for" corner case. A primary role for an SSD drive in the system is pretty much a whole Mac product line up mandate.
The highly sealed cases aren't. The Mac Pro 2013 didn't go that way and neither did the previous ones.
The Mac Pro can't be a headless iMac Pro with an almost 100% match in characteristics. However, few are likely confused about the differentiation of the Mac Mini , MBP 15" , and iMac Pro even though they all have 4 Thunderbolt ports. Differentiation doesn't have to limited to just 'x86 core count' or 'GPU chip used in primary display duties'.
This is a fair point I wasn't really referring to. Thunderbolt 3 was basically a given, and I guess you can assume it'll include >2 USB-A 10GBps ports as well. But that's not much to sketch a machine out of.
If Apple is waiting on Cascade Lake derivate Xeon W solutions then Q2-Q3 would line up with being radio silent this last month. [ If so I'd still expect them to say 'something' by April though. ]
The Xeon SP (cascade lake) won't ramp to volume and all SKUs until Q2 19.
https://www.anandtech.com/show/1361...oses-cascade-lake-xeon-scalable-launch-window
How Intel gets Copper Lake out in late 2019 is somewhat of a 'go figure' if they aren't even getting its predecessor out the door a quarter and change before that. Unless it is more so of a socket change and microarch tweak.
I just assume "delays" for every bit of Intel news I see.