Thank God it is so...! ;-) All Series III mixers (except the 16R) now have a 64x64 matrix for USB and AVB, which adds a lot of flexibility to the whole ecosystem. But in reality you can not use more than 34 USB streams with the 32 channel mixers. Only the 64S allows transferring data on all 64 channels. Nethertheless, all mixers can use the 64x64 AVB matrix, which is essential for networking (consoles, rack mixers, stageboxes, personal mixers). USB and AVB are totally separated "worlds". If you don't use AVB, simply forget it...
The song templates in Studio One show the (theoretically possible) 64 USB streams, but the hardware limits this, therefore it does make sense to create your own template. Simply delete the streams and channels you don't need and design the template for your mixer and situation.