No. There is no requirement to come to the events regularly. Just come when you can and when you want.
There are some people who see the benefit of coming to most events, and there are some people who see the benefit of popping by once every few months. Its what suits you, so if you can come, then come, if you can't, don't feel guilty! Come when its convenient for you, or you can stay connected with me on linkedin.
No matter the frequency you come by, I'd be still delighted to have you join me for coffee!