[Legbreaker]

Would drones be in use in a parallel/alternate world such as T2k?
Possibly.
Would they have seen widespread use?
Very doubtful given the technical limitations of the mid 90's.
Would many/any have survived nearly half a decade of warfare without adequate replacement parts, servicing, fuel/battery replacements, etc, etc, etc?
Almost certainly not.

UAVs/drones typically operate at relatively low altitudes (except for the big hellfire carrying ones of course, but they're more like unmanned aircraft). Given those fairly low altitudes, it's almost a certainty they're going to attract small arms fire, or even get caught in explosions (grenades, mortars, etc) for the more tactical level ones.

The larger ones operating at higher altitudes are sure to be targets for SAMS, AAA guns and other aircraft too, and to my knowledge, generally lack the ability to effectively fight back (yes, I know some have defensive systems which is why I said "effectively").

So, to make things really simple, there's no need to include them in a normal T2k game EXCEPT on very rare occasions as a macguffin or in the hands of the opposition. Their frequency of appearance should be about the same as just about any other type of aircraft and for more or less the exact same reasons.