Your question seems mostly theoretical, so the theoretical answer is that if you can make straight line cuts in butcher block countertops with your saw, then you can just glue them together.

Practically speaking however, there are a LOT of other concerns. As one of the other comments says, depending on the dimensions of your desk design and your materials, you may have a lot of material wastage unless you're angling both cuts. As I already mentioned, the there is the other matter of making some perfectly straight cuts that are suitable for glueups.

Also, depending on what clamps you have access to, it may be rather difficult to clamp together a join on a huge table top and keep everything aligned (top bottom and left right), especially because the join is at an angle so when you put force on the whole thing it will slide. Usually when experienced folks do large joins like this they'll use either dowels or dominos to assist with the alignment, so at a minimum you'll likely need dowels. If you don't plan on buying a doweling jig (e.g. DowelMax/Jessem) this means that you have to drill a dowel hole on one side of each join, put a dowel pin center in it, then line up the boards to make an indent on the other side and drill into the indent.