Can you post the link to the document you are referencing? Also, are you generating the MoH multicast stream from the router; or, using the ccm-manager music-on-hold command to enable support for it from UCM?

Generically speaking, the various SCCP profiles (MTP, Conferencing, Transcoding) are all capable of coexisting. Obviously those which are done in hardware are limited by the DSP resources you have available. MTP can actually be done in hardware or software using the router CPU. This is done using the 'maximum sessions software | hardware' command. If you do it in software you will need to load test and pay attention to the CPU and memory utilization of the router. If it exceeds 70% CPU utilization under load you need to scale back the quantity of software sessions configured.

I have configured many routers that have an MTP profile registered to UCM - especially more recently for TRP use - and also specified ccm-manager music-on-hold. I would be surprised if there is current documentation indicating these should be mutually exclusive.