Contrary to popular belief, HBO Go doesn't have "everything" HBO ever aired. Some of that stuff wasn't produced by HBO either. HBO Go has a ton of old series, but not all.
I know Tales from the Crypt was sold to NBC, at least for now. It airs on Cloo. IOW, HBO does not own the rights to this series right now. Not sure about the other three listed.
Yeah there are a lot of old series and many HBO movies missing. I suspect that there are rights problems for streaming that were of course not thought of when they were made since streaming did not exist.