Nice meme.

However, couldn't also Eärendil be considered?

Edit: found another possibility:

Legolas is the geographically-closest “elf-prince” to Erebor, where the coat was found. But it’s made of mithril, and that can’t be found in Erebor.

So it was probably forged in Moria. The mithril was definitely mined there. We don’t know exactly when, but we know Moria bordered not one, but two elf-kingdoms (Lorien and Eregion).

Elrond was Gil-galad’s right hand elf, and probably could have claimed the title of high king after the Last Alliance, although he didn’t. He also lived in Eregion for a while, and met his wife in Lorien. He had two sons, both born well before Moria fell to the balrog.

Conclusion: it was forged either for Elladan or Elrohir. They wore it, outgrew it, and gave it back to Durin’s folk, who then brought it with them into exile.

I mean, the real reason is that Tolkien simply hadn't thought that far around the story yet, so the line wasn't meant to be referring to Legolas.

I choose to believe it though.

Funny but not so accurate. We don't actually know when Legolas was born, we don't know that the mithril coat was actually forged in Erebor (it could certainly have been brought during the resettlement from the Grey Mountains), and we don't know what "some young elf-prince long ago" actually means and that none was born since the fouding of Erebor (I don't think we have an exhaustive list of noble elves from the text).

My serious interpretation is that "prince" here isn't being used literally to describe the son of a hereditary ruler. Elven lives are so long that they can't possibly have traditions associated with a king dying and his son becoming the new king. Therefore I think "prince" means an exceptional elf, not the king but someone worthy to rule.

(A counter-argument: the mail fits Frodo because it was made for a child. A child wouldn't be called a prince unless he literally was one. My reply: hobbits are short but stocky. Armor made for a slender adult elf could fit a hobbit, although it would be longer on him than it was on the elf - a chain hauberk rather than a chain shirt.)

Couldn't it have been an heirloom from an older elven prince