שלומי is a Common nickname for שלמה.

I knew a man called פלטיאל.

If אלידד and אלדד has the same meaning, so it is still used.

עמיהוד is rarely used.

שלומי is a Common nickname for שלמה.

I knew a man called פלטיאל.

If אלידד and אלדד has the same meaning, so it is still used.

אליצפן , עמיהוד are rarely used.

Names come and go... It's a matter of fashion. Do you think that we use the Nessim names less then we use other biblical names?

I don't think there is a special dislike for those names, you can call your son פדהאל (awesome name!)