Pattern recognition is a topic in machine learning. Of the questions tagged pattern-recognition, only a handful are related to machine learning. The rest are of the form "What is the next item in this sequence?" It does not look like the tag is being usefully applied. Should we remove the tag from the other questions, or create an alternate tag for them, or do nothing and allow pattern-matching to be ambiguous?
As the tag has no wiki summary, I see no current issue with its dual use in covering the fields of machine learning and also the more colloquial "identify this pattern" usage.
Machine learning is a specialized field, open really only to advanced practitioners of applied mathematics and a few engineering disciplines. Math.SE has a more broad audience, and problems like "What follows in the pattern 2,4,6,8,___" are much more likely to arise, if only due to their (IMO unfortunate) frequency of occurrence in elementary education. Problems like this probably need a tag, for that reason, and pattern-recognition seems a good a tag as any, really.