No, hypo's can be hypo's without the clear nails. The hypo pastel line from what I understand have the traits for the clear nails and are referred by some being TRUE hypo pastels. TRUE by them meaning showing the differential trait of the clear nails.
And yes, again you are dead on with the color being pastels. Is this what is referred as the TRUE hypo pastels. I don't believe it so. Is it a name given to pastel colors. More then likely.
Pastels Colors by definition do not have brown or solid black, this could certainly lead to people calling a hypo meaning lack of dark pigment and a pastel coloring Hypo pastels without the defining clear nailed trait. Leading many to separate the two by adding (with clear nails) or adding TRUE. I never seen any body add this to any thing else except pastels.
Many have one, two pop up it's possible, Like you said in the wild all these are available, but not done regularly like hypo pastel lines. Or I guess TRUE hypo pastels, or (clear nailed) if you would like to separate the two, from pastel coloring.
Yes, I guess you can say I'm saying there are lines of pastels that just show the clear nails and breed true.
People are breeding redflames to sandfires getting pastel colors and calling them hypo pastels. Do you agree with this? Seems dangerous to me. Really confusing the two and leading people to have to make two names one TRUE one pastel. This is the bottom line. I don't agree with people attaching names without any truth in the breeding. Two top breeders will not put that name to a pastel colored dragon. I have seen this they are getting whole clutches with clear nails which are in their and mine the TRUE hypo pastels. For years now with regularity.
-----
Mystical Dragons