I’m not a linguist, but an Austrian
I believe it happens all the time, for example:
“sagen” -> “sag’n” (to say)
a more extreme example:
“gewickelten” -> “g’wick’lt’n” (past participle of “to wrap”)
From my observation, different dialects do this differently. In Austria, many dialects shorten many of these vowels to the point of omission. In the first example above, no one ever says the full “e”, except maybe for emphasis in a stage drama or so. In many places the contraction even goes further and turns the “g’n” to a “ng” sound. In the second example, the first “e” would not be shortened in formal speech, but the second “e” would be.
Please correct me if this is actually a different situation! It certainly seems similar.