Well, those that hit you best score ever on a Rock Band 4 song as a band or individual, may have to head back to the game in April. When the exploits previously mentioned go into play, Harmonix will also be updating a bunch of other fixes that impact some DLC. While you won't have to re-download any tracks, you may have to set a score again for individual tracks as both a band and for instruments (or vocals) once Harmonix gets done. Below is the list of all the fixes going in, but you will want to check out the nifty table on the forums to see the impacted songs.
Here is a list of DLC bugs that will be corrected:
•Bad tempo maps, i.e. the gems aren't on the beat
•Solo and harmony lyrics not lining up with their note tubes
•Missing solo and harmony lyrics
•Keys parts that have been remapped to guitar
•Missing characters in the lyrics, especially some foreign characters
•Missing drum submixes
•Score exploits when songs were looped too close to their beginning
•Hopos that were preceeded by a non-hopo
•Overlapping fills
•Bugs in the graphical display of the vocal hud
•Guitar solo authoring and endless solo mode
•Pro vocals improv
•Fixed a handful of audio files
•Camera authoring issues
•Light presets, including adding many that were missing
•Post processing fixes
•Missing venue FX events.
•Character animation bugs, including fixing some jerkiness in the limbs
