Sometimes it can be called cheap workers who come from villages in Western Ukraine in search of work. (Because they used it "vuiko" appeals to any men.) Therefore, it can be offensive.
Historically: Стрийко (stryiko) - uncle, father's brother.
Вуйко (vuiko) - maternal uncle, mother's brother.
Дядько - any uncle.
Nowadays is commonly used only the last term. It can also mean any elder man, and not only uncle. The same applies to aunt. This could mean any elder woman. Widespread is the use of diminutive forms in the Russian version - "дядя" (diadia), "тьотя" (tiotia) but this is not a literary norm.
Sounds OK to me. Please remember that real sounds produced by native speakers may be different from what you might expect from just reading the description of the sound. To me the sounds in дядько are textbook examples of denti-alveolar [dʲ] and [tʲ].
Some variation might be found among speakers, I assume. I cannot comment on Ukranian, but in Russian [dʲ] may get a slight hint of [d͡zʲ] depending on the speaker and the speaker's mood (while devoiced [tʲ] may become a bit like [t͡sʲ]) .
I came here to say this, but you summed it up MUCH better - I know a bit of Russian, and this is just how a soft D pretty much always sounds. I didn't actually question it until I saw all of these comments!
(Btw, it took me EIGHT tries to write "Так" instead of "Да" for "yes"!)
To be honest I don't hear that in audio... Yes, there should be no ж sound in this word. However, I must admit that we can sometimes hear that in speech and there's really no explanation. I had a professor who pronounced word "діти" (kids) almost like "дзіти" and we just had to deal with it :)
I think it really just sounds like it's making a "ch" sound because (1) you're either not used to it or (2) how close together the sounds of the words are arranged. From what I've gathered so far and from what a friend told me, the ь in Ukrainian can be silent, as it is in this word and others. Дядько is properly pronounced "dyad-ko". Hope this helps
The palatalised д/т is proounced with the blade of your tongue, i.e., compared to a usual dental д (т) a wider and flatter area around the tip is used .
The exact realisation may vary. In present day Russian there is a certain trend of mixing in a tiny drop of dz / ts into this sound (meaning, the resolution of the consonant has a slight S to it).
Ukrainians still prefer a cleaner, more abrupt sound, like in this sentence.