I was considering doing this myself the other day, but a friend's words came to mind that by discussing an idea socially, people tend to feel a bit of reward that they otherwise would have to wait until completion to obtain. Talking up a project can make one lose the motivation to actually complete it. Still, that's all on the submitter of said goals/progress/plans to consider.
They were probably remembering this Ted Talk. Whilst I think there's some truth to it, I think it does little to dissuade those who are truly committed. Either way, It wont just be "I plan to do this" and then no follow through. The difference here is that everyone will be holding each other accountable. Constant updates and/or evidence on how you have worked towards your goal each week and reinforcement of your plans is the idea here.