Indeed, it may not be included in standalone. However, if the Shader.Find is unable to locate the desired shader, it should report an error or the pink "missing shader" (which does not always happen).

I had a similar issue (objects not being rendered on build - using DrawMesh), I used Shader.Find to create a new material at some point. It seemed natural to me that the shader would be included (since the same shader was used in other objects), and since neither material nor shader was null (and no error reported) I assumed everything was ok with the material. However, the problem persisted (though no pink material or error reported). In this case I chased the issue in a hole different direction since it appeared that Unity was able to successfully find the shader. I even hooked up RenderDoc to find out that the draw calls were not even sent to GPU (which its also weird).

It took me a couple of hours to find out (in trial-and-error style) to finally discover that if I used an explicit reference to the material, it would work.

Long story short. There should be a better handling when Unity is unable to find the shader. Perhaps report a warning or error - even null would do. I was surprised (and disappointed) to find out that the shader was not found and, at the same time, it wasn't null (which doesn't make any sense to me) and no error was reported.

I made a quick demo to illustrate the issue. In this case, since there is an object in the scene and a material in the resources using the standard shader, Shader.Find("Standard") should work (I believe). However, the results from the editor and standalone are different, since the cubes are not drawn at all on standalone. https://www.dropbox.com/s/1e8488a2y9zah08/DynamicMaterialBug.rar?dl=0

The shader in the material reference indeed does not exist, as it is not included in the project. This appears to be by design.

From https://docs.unity3d.com/ScriptReference/Shader.Find.html:
Note that a shader might be not included into the player build if nothing references it! In that case, Shader.Find will work only in the editor, and will result in pink "missing shader" materials in the player build. Because of that, it is advisable to use shader references instead of finding them by name. To make sure a shader is included into the game build, do either of: 1) reference it from some of the materials used in your scene, 2) add it under "Always Included Shaders" list in ProjectSettings/Graphics or 3) put shader or something that references it (e.g. a Material) into a "Resources" folder.

My problem resolved itself when I put the 'Standard' shader I was using in Assets/Resources.