Adding any datapack that features a custom music disc using the recently-added jukebox changes triggers the warning that the save uses experimental features and may not be supported. From my own research, I cannot find any evidence that this is meant to be the case (but I very well may be wrong). It would be nice to use these datapacks without the risk of being unable to use the save in future versions.
MC-274210
Custom Music Disc datapacks trigger the "Experimental Features" warning
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