no, however the risk gets greater that there will be complications the older he gets when and if you neuter him.
I know your not in a position to get him a cage mate right now... but if you are going to get him a friend at some point it would be wise to get him neutered before hand.
1 the hormones take about a month to simmer down, 2 you really don't need any kind of inbreeding since he's not lineaged you will have no idea if any potential cage mates are close relatives. 3 typically, reasonably priced male gliders are intact, two intact males can get a long but there is a great potential for them not getting along. 3 females are not "fixed" unless medically necessary and that is rare so if any one tells you that they are misinformed and ask for vet bills showing the procedure was done.