Found an old interview with Mike Anthony. I beleieve this is the exact time era of Dave doing the 2 songs with the band in '96, right when Sam left. Its an interesting read. Including the part where Mike says "Right now we are gonna finish up these 2 songs with Dave and start looking for a singer to go on tour with, cause I just wont tour with Dave". So according to this interview there never really was any plan with Dave after the 2 songs after all.
http://www.van-halen.com/newsite/515096.html