Not communicating causes problems for everyone you didn't communicate to.
You want to meet? Fine: post it on the forum with a date/time/location and everybody that is interested can either list their availability or confirm they will come or be absent.
You said you would meet but plans changed? Fine: post it on the forum in a timely fashion so everybody else is informed about this and can change plans if required.
Not enough people confirmed? Fine: post it on the forum and formally cancel the event.
You want to play but not in the location suggested? Fine: post it on the forum and add a clause that you are only available to play in location X/Y/Z on date/time.
Whatever your own intentions might be communicate them to the other people, changing plans or ommitting information impacts other people.
Also the forum exists for a reason: communicating with all at once.
If you go arranging private meetings you do not give a chance to the other community members to stay part of the community. And this community is already very small.
Post it on the forum if it impacts other people, do so in enough detail and on time for others to see the post.