I am surprised that some people feel that coordinating pax boarding wit the crew is not the job of the FBO.
To me the FBO is basically a handling agent. They arrange or provide the requested services (fuel, catering, water, toilet, cleaning, pax handling etc) and of course need to check that the crew are ready before bringing out pax. Imagine gate staff boarding an airliner without checking that the crew are ready.
With regards to weather and notams: I think it is not asking too much to have this ready and printed for the crew at no additional charge. In Europe this is usually the case at the better FBOs. Yes, we can, and often do, self brief using smartphones etc but some (many? most?) commercial operators require that there is a printed copy available. Also helps when you are being ramp checked. Of course the requirements will vary from operator to operator (and also depending on the governing authority) but having this info ready for the crew is a fairly basic service I think.