See https://www.wikidata.org/wiki/Wikidata:Properties_for_deletion#Property:P5482. The replacement of the current LilyPond property (which uses the string datatype) may necessitate an increase in maximum string length for the musical notation datatype. The current limit for the datatype is 400 characters, but there is at least one existing value which is longer.
There may, of course, be licensing issues (as noted in the linked discussion). However, I don't think it should be overly concerning: normal wiki pages (obviously) don't have similar length limits for content; and copy-and-paste copyright infringement should be more difficult than with other properties, because the user needs to either deliberately find a non-CC0 LilyPond source file or be able to write valid LilyPond syntax.