Personally I think the risk to jet traffic is virtually nil, so the proposed media release has the feel of crying wolf to me. If blocked transmissions is really a problem then combining frequencies and competing with new IFR students making reports etc. is a much bigger issue.
I see it as an occasional annoyance for ATC than a serious risk, and if it becomes a problem they have the ability to deal with it.
The risk of collision between someone using such a strip and passing traffic is also miniscule.
The only real risk of collision is between aircraft trying to use the same strip (or in some cases strips in close proximity). This means that the only people who really need to hear the transmissions are those people - but people using the same strip DO need to be on the same frequency. A dedicated frequency makes perfect sense for this - the area frequency does not.
The real risk from the change is that many (I suspect most) will keep using 126.7, and will be on a different frequency from anyone following the CASA rule.
I know that there are a lot of unmarked strips in the area where I fly. I have spoken to a few people who fly out of them. My conclusion is that:
- Many make no calls because it is their own private strip and nobody else is likely to be using it
- Some make calls on 126.7
- Some I suspect used to make calls on 126.7 but now will make no calls
- Nobody makes calls on area
Most of the people with unmarked strips don't want them marked or the location generally known. Apparently there are some ATOs who view a private strip as an ideal place to test precautionary search procedures, but the owners are less than enthusiastic about 50' passes over their backyards. I couldn't tell you whether the ATO/student announced their intentions on the area frequency...