You're confusing two different things. Ye as a plural pronoun is a bone fide archaic English word, ultimately sharing an etymology with the still-extant "you". "Ye" as an article ("Ye olde...") has the history you reference, where the y comes from a stand-in for a thorn (th), and so was not supposed to be pronounced as "yee". But ye as a pronoun (by far the most common usage, I think, and the usage in the poem) is just a normal word and doesn't share that history.

Ah yes, the thorn was the one I was looking for. I remember reading something about that when looking up the reason old pub signs in England sometimes had the thorn and often 'ye' but are always actually supposed to be 'the' in technically correct form.

> wonder (with my limited knowledge on the exact nature of the language) why we still print 'ye' if the 'y' was a shorthand for 'th'

Where it is pronounced “the”, it wasn't really a shorthand for “th” it was a rendering of “þe”, because the cursive “þ” came to look like “y”. Because we don't use “

But, actually, in Ozymandias it's not that form, it's the pronoun, which was actually pronounced “ye” and spelled “ye”, an alternative form of “you”, not the article pronounced “the” and spelled “þe”. https://en.m.wikipedia.org/wiki/Ye_(pronoun)

Coming from germanic languages where a lot of pronouns are available but only a very small subset is used today, the ye/thou pronoun context makes more sense now with that explanation.

In this instance, “ye” is the plural form of “thou.”

And (if I read the other responses correctly) thou is similar to 'you' in pronoun terms, right?

Because even though the 'y' was originally a substitute for the thorn rune, it then passed into common language with the 'yee' pronunciation. Given that this poem was written in the 1800s, I would guess it's meant to be pronounced with the 'y' sound and not a 'th' sound.