I doubt it. The current Mini is the entry level desktop unit and probably will remain the same. It gives Apple a machine for those who want or need a desktop.
Except the Mac Mini rumors have talked about a new Mini with a "pro focus" and higher price - which seems strange if there is going to be a new Pro as well.
On the other hand, since the Cylinder hasn't been updated since 2013, and any still-in-use Cheesgraters are effectively becoming more like Hackintoshes, the majority of actual "pro" users must surely have given up and switched to Windows or Linux so that they can use purpose-built systems and have a reasonable expectation of upgrading them when the tax/leasing cycle dictates.
For the remaining enthusiasts, and developers, A i7/i9 Mini with a half-decent dGPU might be a better option than a Xeon shoe-horned into $5000 aluminium shard ($300 AMD GPU in a $1000 eGPU enclosure extra). Or, maybe, Apple will get over themselves and make the true Pro the mini-tower PCIe "pickup truck" system that fills in all the gaps between the Mini, the MacBook Pro and the iMac Pro.