Policy has been the same since the courses opened: preference is to have foursomes, and thus singles are paired with others whenever possible. If his concern is playing partners reaction because of his own ability, then be aware of the following based on more than 30 years of playing the Disney courses while visiting WDW:
1. About 85% of the time the golfers you are paired with score in the 90s to low 100s on the Disney courses. The courses are not overly hard but it is easy to lose balls from wayward shots. If choosing a course to play be aware that degree of difficulty from high to low (with none being easy) is Palm, Magnolia and Lake Buena Vista
2. There is a risk of being paired with very good players, including potentially those who play from the back tees, but most often when that occurs, it does not include the entire foursome and those good players are usually very pleasant to golf with. The risk of getting only very good players in the group is higher for the first hour or so of tee times in the morning.
3. The sin most despised by many players you are paired with is slow play not play that requires many shots (which itself does not mean slow play). Even then, the issue is not a major one at WDW because the typical round is 4 1/2 hours and even a little more, particularly if your tee time is after the first hour of tee times. You do often get those who definitely like to play fast in the first few tee times.
4. In the well over 150 times I have played the Disney courses, I have been paired with those I would consider persons I would rather not play with only twice and neither time was it an issue of player ability. One involved a father playing with his 13 year old son and the father continuously criticized and cursed at his son whenever the son hit a poor shot. The other involved players whose racial disparagement comments were continuous.