Are the acronyms FYI, BTW, LOL, WTF now considered "normal" words?
I'm curious about the reason for calling these acronyms "elitist," but a general answer to your question is
- yes, these acronyms are being assimilated into more general use, but
- no, these acronyms are not becoming words with significantly different meaning.
Regarding the reference to SNAFU, FUBAR and OK, the argument to be made is whether the original meaning, not the origins, is lost. "OK" is deceiving in that, while almost no one could state what the earliest-recorded expansion of the acronym is, we still use it in the same general meaning. The expansions of the other two can be sussed out with a bit of work, as they come from actual words rather than colloquial satire. These, too, are still used with the same general meaning, though we choose to ignore the masked vulgarity. Further, the expansion of shorter acronyms, such as FYI and BTW, will quite possibly remain in the common understanding until the words actually fall out of use.
Snafu and Fubar have assimilated further than will "FYI", "BTW" and their ilk. "FOO-bar" and "SNA-foo" can be pronounced as words. Will people actually start saying "FWEE" or "BE-twa," outside the ironic "B-T-DUB" that Tonza offers? I'm uncertain, but I have a feeling the answer is "no."
"OK," IIRC, may be in the extreme minority as it has actually been turned into the word "Okay." "LOL" is sometimes made "LOLing" or "loling" as it can actually be pronounced coherently as a word-construction, but I don't see the same fate for these other acronyms.
Regarding stacker's opinion, I don't believe this to be a difference between acronyms and abbreviations. Acronyms are built using the initial letter of all or most of the non-articles in a phrase. An abbr. is a shortened version of a word, where a number of characters are lopped off from the end (and sometimes inside) the word.
And, FYI, SCSI (Small Computer System Interface, pronounced "scuzzy") is an acronym.
In spoken English I have heard F-Y-I but not OMG, LOL, or WTF except when specifically emulating texting style or teasing someone about it.