I think you misunderstood me; I was indeed discussing the “disappearing R” of library, February, particularly, veterinary, etc. Where there are two Rs in the word, many native speakers of English, regardless of rhoticity, have a tendency to drop the first.

Incidentally, my speech is rhotic, and this phenomenon, as I’m sure you are aware, is just as common in American rhotic speech as it is in English non-rhotic speech. For that matter, it is also observable in American non-rhotic speech (which gets rarer by the day); I don’t know enough about English rhotic speech (in the southwest, pockets of the north) to comment.

For what it’s worth, as a child in New York City, I learned “January, February, March, April, …” as [ˈdʒænjʊˌɛri, ˈfebjʊˌɛri, mɑɚtʃ, ˈeɪprəl] and so forth. In fact, I remember being taught that the first R in “February” was a silent letter! (As a tiny child, I swallowed this whole.)

I haven’t heard R deleted before an L in the same word, but perhaps I haven’t been paying attention. I’ll probably start noticing it everywhere now …