If the tail was bitten off it will regrow. If it was a birth defect it can't grow more tail past the natural end of the tail.
They are not likely to drop a tail but all skinks, even Bluetongues regrow a tail which is cut off by some form of attack. They never regrow like the oringinal so will end up with a shorter less patterned replacement.
My first baby Pink Tongues were with both parents in the enclosure and I sespect the male bit the tail off two which are pictured. Since this first time I remove the gravid female to her own enclosure till she has the babies and then return her to the males enclosure.
The one with the shortest tail seemed fine and suddenly a died a few days later. The bite may have hit the body as well and caused internal damage.
The other was fine and a picture is attached of the regrown tail.