Why should a group spend that extra effort on uploading later to time it when they can just upload same time as on their own site, and just set a time?
What's wrong with seeing a counter to when it will be available, when it lets you know content is coming rather than series being dropped? (Can even find links to their site if you really lack the patience.)
If you're so upset about it, you should complain to the site staff and ask them for a profile setting to hide delayed chapters until their release instead,
rather than complaining at groups using existing features the way it suits them. (Atleast if you have the capacity for logical thinking.)