Thanks to some coaches that I know socially, plus ChalkBucket, I have some understanding about the differences offered in Australia. From my experience, better than most of the parents with children a similar age (young) which is perhaps worrying. Most of my information is from here.
If I had not explicitly asked, the difference between SS, NDP and IDP would not have been explained to me. IDP was not even mentioned at our previous gym as it was not offered, which is fine, but when that gym then puts a barely 4 year old in a development class with 6 year olds, then perhaps they should have given me hints to look elsewhere for younger age groups.
I don't think it is essential for parents to be overly informed about what is out there, because the whole array of choices is actually mind boggling. Few will even know the physical strengths and weaknesses of their child, let alone which gymsport and stream would be ideal.
But there does need to be some kind of understanding of differences when there are different expectations in terms of levels of commitment and hours/cost. Your gym may do a better job of giving just the right amount of information, but a lot of gyms provide basically no information and then parents suddenly find themselves with a whole lot of hours of gym time to take their young child to and lots of juggling of other kids activities.
From my experience (from conversations with coaches that I am friends with, not conversations about my child) coaches tend to assume that parents asking for information about the different programs are doing so because they somehow have this idea that their child will go to the Olympics etc
If the difference between say IDP and NDP were clearly explained at the outset, this would allow parents who really don't want to make the time commitment for whatever reason, to make an informed decision early, rather than it becoming a big deal further down the track when there may be helpings of guilt and disappointment mixed in.
Websites often have a short blurb about program differences, but most parents don't seem to read it. A 10 minute conversation when the child is invited to a particular program would go a long way.
Parents get upset at the lack of information, coaches feel hassled and feel that parents don't need to know this information. Head coaches end up having to be administrative people who are perhaps from stronger coaching rather than business backgrounds, clubs run by committees, non-profit organizations etc. mean that this early communications seems to be missed.
I'm sure some gyms are wonderfully organised and perhaps even either talk to parents when the kids enter a program or provide a handout or something, but it hasn't happened to me at either of 2 gyms.