+1 The usefulness of these directives depends upon a number of factors, including the nature of the project, and the maturity of the project. These directives will be very handy for my workflow in early stage development and integration. These are common in other languages, so they should not be foreign to the vast majority of developers.
Adding an #info or #message would require changes to tooling that recognizes errors and warnings from compilers in order to surface this output to users. More importantly, I have never seen an informational message from a compiler and such messages see to be at odds with the common design pattern that compilers only emit output for problems.