"The patches are sent out as and when necessary"
Yeah dude we know.
Every day, we have to make decisions on what stories to write up: what can be completed in time before something gets too old. Stuff has to be prioritized. There also has to be a healthy mix of stories, it can't all the the same stuff everyday.
So if there are enough Linux world patches to fill a monthly roundup, then that may be the best way to summarize it, because we may not have the time or people to write a story every time a patch arrives.
Obviously, the latency in rounding up the patches is non-optimal, and critical ones could be written up immediately because they prioritize over other stories.