no, both words have 4 syllables and the final i is a full vowel, it has to be pronounced (it is 'sonor', or stressed). ”Cei-lalți” has two syllables only (the final i of both syllables are semi-vowels, making 'consonant' sounds). ”Co-pi-ii” is three syllables (engl: ko-'pee-eee). The non-articulated version is also two syllables only ”co-pil, co-pii” (engl: ko-'peel, ko-'pee).
If the word ”copi” would exist in Romanian (it does not), it would be pronounced in a single syllable (again, we have very strict rules here), ”kopi” with a very short, palatalized ”ee” sound at the end (example of valid Romanian words: nori, peri, țări, țâri, mări, cari, etc).
In fact the TTS bot pronounces the given sentence quite well here...
Yeah, I reread the posts above (and edited mine a bit), with consonants, etc., but the real thing is about syllables and not consonants. In Romanian we have very strict rules to split the words into syllables (most probably because the letters are always pronounced the same, and there is no concept on "spelling" as in English, where you could have words with the same pronunciation but different writing... well... textually we can say "tell me letter by letter" - "spune-mi pe litere", or "spune-mi literă cu literă", when we do not understand a word, but the concept is not exactly the same...), so, for example when the consonants stay with the first syllable, and when they go to the second. Here, a better example and easier to be understood by English speakers, would be with "res-ta-u-rant" (singular, 4 strokes) "res-ta-u-ran-te" (plural, restaurants, 5 strokes, see what's happening with the double consonants). Also pay attention to the "a-u" pronunciation (as in "a-u-to" and not "o" as in French and some English words).
"ceilalti" has two consonants before the almost-silent 'i'. Come to think of it, 'consonanti' does too. in both cases the 't' sound becomes a 'ts' sound for euphonic reasons. All I'm saying is it's a bit complicated, and people learning Romanian should have it pointed out that an 'i' on the end of a word can be pronounced two ways. And then there's 'copiii' which is not pronounced cop-i-i-i. It just is worthy of note that those learning the language will need to pay some attention.