Certain verbs such as drink, speak, and swim seemed to be misused more and more with this tense. Is this a regional phenomenon or common in all English speaking countries? For example, in southern Illinois and western Michigan many people say, I have spoke, I have swam, or I have drank and opposed to using spoken, swum or drunk.
closed as not constructive by Bill Franke, FumbleFingers, John Lawler, Barrie England, coleopterist Jan 28 at 13:36
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The short answer to your question of "Is it Disappearing?" is no.
I generated Google ngrams for all three examples you gave "have swum vs. have swam", "have spoken vs. have spoke", and "have drunk vs. have drank", and I found that for all three usages, the usage frequency for the incorrect usages has remained stable and low for a long time, and for all three examples, the incorrect usage was in fact more common in the past, not less common.
Your observations are probably just an example of the recency illusion, the belief or impression that something is of recent origin when it is in fact long-established.