I had my transmission fluid changed on my 96 E38 and it has developed a slight whine between shifts . No other problems. I know they used the oe filter and oe fluid. Any thoughts and do you think it will go away in time ???

If you're POSITIVE they used an OE filter (and by that I mean that you yourself saw that it said Filtran on it) then its low on fluid. They either forgot to turn on the lights to bump up the idle when filling it or didn't use the right filter. It will not get better.

Use only transmission fluid from BMW
Wy change the oil for your transmisson it is
for life time the 7 series from 1998 end up only tip it op when needed.

trans fluid is not for life. It should be changed regulary. I've succesfully brought my 4 hp22 (89 E32 160,000 miles) back to life by doing just that. Toping it off does nothing but add more fluid to the crud already in there. I did a series of slow, calculated flushes: drain-fill with drain open-close-fill-drive around block-repeat I did it again 3000 miles later and will do it again very soon this time with Amsoil to complete the process. After that I plan on every 10,000 miles. It fixed my hard shifting and brought back tons of torque and acceleration and the smile to my face when I drive it.