Let me phrase my argument a different way. I used to workshop all of my poems on Eratosphere, so I assumed that most people here who were interested in seeing a poem had already had an opportunity to do so earlier. Now I write a certain number of poems that I don't workshop here. If one of them gets accepted, I would still like to have people here know about it so that they can read the poem if they wish. Gaining readers for poems is one of the (few) perks of publishing online. I also go through periods in which I am too busy to read the poems of others when they are workshopped. Hearing that a poem has been published online gives me one more opportunity to connect with it. So I am all in favor of everyone letting everyone else know of each poem that gets published.
If we start setting standards of how "important" a publication needs to be before it can be mentioned here, there will be a lot of bad feelings on the part of many members, and the whole process will encourage snobbery, even if that is not the intended effect.