There are a few misconceptions about leo morphs here, so let's get them straight first.
Leucistic - there really isn't a true leucistic leo yet. Even blizzards don't cut it since they can produce melanin and don't all have blue eyes.
Leucistic used to be applied to what's now called the patternless morph. They are still called leucistic once in a while but it's not correct, and most people are now saying patternless.
Carrot-tail is technically the red at the base of the tail, but to be completely correct, it should be used with leopards that actually have the true carrot-tail genes. Almost any leo can have orange/red in the tail, but the true carrots have a particular shade of orange, very few if any faint spots in the orange and even that should be mostly towards the end of the tail where the orange fades.
Patternless leos often have orange in their tails, it's nothing new. I don't have a picture of my patternless breeders from years ago, but they had a lot of orange.
I did dig up a picture of one of the patternless albino offspring. They look quite similar to a patternless and can be confused with one quite easily. This one happens to have true carrot-tail genes from her great-grandfather (or possibly great-great-grandfather, I lost track

)
The carrot-tail genes show up as a solid orange/red section at the tail base.