I did the DW2 expedition and the first waypoint for that was the Tourist Beacon in Pallaeni.I have not heard anything specific on this subject.
I'm not sure if it is really possible to specify a particular place in the system as a waypoint for an EDSM expedition. At least in those I've participated just visiting the system did the job. I found out that my friend got the mark for Sol on the second attempt. I will ask him if he docked somewhere or scanned something to achieve this.