If you go to console (`) then type switchmatch EXE_Overwatch then type SGPawn PrimaryWeapons (A_AirStrikeMarker_02) then spawn as whomever and throw it there will be red smoke then a faster airstrike then Skyhammers usually one.
Is this probably a earlier version of Sky’s Airstrike?
Yes, this was the earlier interpretation of Skyhammer’s airstrike, besides the same airplanes the marker takes longer to detonate as it takes a moment to explode after releasing it’s smoke if I remember correctly. My guess is that enemy players easily spotted the smoke and thus take cover or the simply design of the laser beam basically showing you the direction the airplane is going that is used now is more appealing along with making it harder to notice, scaling the visiblity on support abilities being from least visible to visible: Kira’s Pillar of Fire, Stoker’s Grenades, Skyhammer’s airstrike and finally Arty’s Artillery.
Edit: Another item from an old build are Grenade_01 and Grenade_02, Grenade_01was regular frag grenades which at one point everyone carried before just belonging to Fragger and Grenade_02 were Flashbangs that belonged to Dazzler, A merc that was removed and later turned to Fragger and Thunder.