I see campaign announcements and requests for spectra coming from many directions with varying degrees of formality. (The ARAS forum for example has specific areas for campaigns and alerts). I have relayed details of some of them on this forum that I have either received direct or seen elsewhere but they can tend to get lost as they eventually scroll off the bottom of the page.
A sticky post which would stay at the top of the spectroscopy section of the forum that anyone could add to if they come across campaigns might work. (Andy and I did try this with my post on target results for ALPY observing and data reduction but it seems to have come unstuck). Adding information about a campaign announced elsewhere would not oblige the poster to coordinate it or follow it up unless they wanted to take on that responsibility. It would be up to the individual contributor to do that with the PI concerned.
Here are a few examples from me on this forum
also some run by Ernst Pollman eg