The reason for the delay is that Harmonix caught a bug in the finalization process for the patch. Harmonix laid out the specifics of the update last month: The patch would include fixes for some "gnarly bugs," including issues related to score exploits, and would wipe Rock Band 4's online leaderboards. Harmonix initially said that another feature — one the community refers to as the "Overdrive squeeze" — was working as intended, but the company changed its tune after an outcry from die-hard fans.
"We had already 'branched' (Development term for 'feature changes are locked, and we’re only working on bug-fixes now') for the update, but this was important enough to add in anyway, post-branch," Harmonix said in a blog post. The studio's fix for the squeeze issue came through testing just fine, but when Harmonix was finalizing the patch, the studio realized that the fix "inadvertently caused a bug unrelated to [Overdrive]." That forced the development team to fix the bug and start the testing process all over again.
Harmonix planned to release the update by the end of January, but pushed it back one week to sometime between Feb. 1 and Feb. 5. Because the update was originally scheduled for next week, Harmonix doesn't have a new batch of songs ready to go; instead, the studio will release both the patch and some new tracks in the first week of February.
With the February update, Harmonix is moving to a more well-defined schedule for Rock Band 4 patches. The studio said in November that it was planning to release updates on a monthly basis, but now, the company is committing to pushing out those patches about a month apart. So whatever patch comes in March is now scheduled to arrive in early March, not just in a nebulous sometime-in-March window.
"We can't promise they'll always be in the first week, because things do happen (like they happened here), but our targets are for the first half of every month," said Harmonix.
As for song exports, Harmonix said it's still working to get song exports for the original Rock Band working for PlayStation 4 owners in Europe and Xbox One owners worldwide. Rock Band song export went live last week, but only for North American PS4 users.
For more on Rock Band 4, read our review.