It is not a sock puppet, but rather an automated or semi-automated account for making repetitive edits that would be extremely tedious to do manually. Administrators: if this bot is malfunctioning or causing harm, please block it.
The delay between publication of an article and it being indexed in PubMed Central varies between a few days and a few months (not counting embargoes, which do not apply to Wikimedia-compatibly licensed content anyway), sometimes even years (e.g. for back issues of newly indexed journals).
Most articles in the Open Access Subset are not licensed compatibly with reuse on Wikimedia Commons.
Only a small minority of the suitably licensed articles in the Open Access Subset have audio or video files associated with them.
The delay between a suitably licensed article being indexed in the Open Access Subset and its video and audio materials being uploaded here is typically around a day or two, but can in rare cases be hours or years.
The usefulness and completeness of the information used for file conversion, descriptions and categories varies by publisher, journal, article and file. Some more details here.