As a result of the insistance of MARC on their network, it is not permissable to interoperate the MARC infrastructure with anything which is non Motorola. This means that it must be MotoTRBO and IPSC end to end.
DMR+ has as it's core aims to create bridges between all popular networks and node types.
It is technically possible to use a DR3000 in conjunction with a small server, typically a Raspberry Pi, and then dedicate one time slot on the DMR network, and the other to the open DMR+ network. This is acceptable within the MARC community as there is no bridge between the two systems.
For now, however, the new software developed in Germany has been installed on the Linux DMR+ master server which allows it to deal with IPSC protocol as used by motorola repeaters without having to use Motorola's propriatary IP Site Connect software.
So yes, essentially, any repeaters joining the DMR+ network will have to leave MARC due to the restrictions that levys them under.
At some stage, we maybe can expect top see some DMR repeaters with a foot in each camp but the software is I belive still in beta.
I hope I've got the technical details right there, and I'd be glad to be corrected if not. I'm not myself involved in the network engineering aspect.