It started out as the former - anglicised pronunciation as a result of teaching in public schools by (enthusiastic but poorly trained) non-native teachers in schools - but now it is creeping back into the next generation of young native speakers who feel embarassed to speak properly at school in front of their non-native peers, who vastly out number them.
Some Galltacht speakers who don't want to "sound like hicks" feel they need their own dialect and mistakenly force their English accents into Irish pronunciation. This is sometimes called "Urban".
There is an alternative standard pronunciation called
lárchanúint (literally "middle dialect"), which retains the native phonemes without dialect-specific markers but avoids anglicising the phonemes. A good example of this is found in
Buntús Cainte (still available through bookstores and also as an online course).
Although
lárchanúint is not popular among native speakers because of its "artificiality" and lack of
blas, it is still considered more faithful to traditional Irish than Urban.
To anyone who doesn't want to learn a specific dialect but also don't want to sound like a school Irish speaker or a "foreigner" who learned Irish, I highly recommend learning (or re-learning)
lárchanúint from
Buntús Cainte (that way you'll only be a short step away from learning a real dialect should you choose to do so later.

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