Presuming this results in a cryptosystem change for Akira, there’s a real number of victims who won’t get their data back as a result of this disclosure.
Whether the number is more than that of victims to date who can recreate this? Who knows
I can’t remember the example (it was a conference talk a few years ago), but I’m pretty sure there’s LE and DFIR companies who also reverse this stuff and assist in recovery, they just don’t publish the actual flaws exploited to recover the data.
It was already disclosed to the bad guys that someone managed to break their encryption, when they didn't get paid and they saw that the customer had somehow managed to recover their data. That probably meant they might go looking for weaknesses, or modify their encryption, even without this note.
Other victims whose data were encrypted by the same malware (before any updates) could benefit from this disclosure to try to recover their data.
Whether the number is more than that of victims to date who can recreate this? Who knows