And I've just re-read the email that came soon after the original end of Finale email, 'the end of Finale, your questions answered.' where it says:

How long will my current Finale installation work?

Finale authorization will remain active indefinitely. This means that you will be able to install and authorize Finale on new devices for the foreseeable future. However, please note that future OS changes can still impact your ability to use Finale on new devices. 

'Finale authorization will remain active indefinitely.'
Does this mean they have changed their original statement where authorisations would end August 2025?

'This means that you will be able to install and authorize Finale on new devices for the foreseeable future.'
Can we have this in less vague terms please?
What exactly does 'foreseeable future' mean?

This has been discussed many times in this forum as well as the unofficial forum that is more trafficked. Originally, the MakeMusic folks gave it a year. Now it's "indefinitely," and that means "likely longer than Sept, 2025 but I wouldn't count on it for a long time beyond that." 

If you're using the same computer for many years, it's likely not a real concern (truthfully, it's pretty unlikely IMHO that a version of macOS or Windows in the next 3-5 years will totally break Finale, but plug-ins and/or audio setups might not be as durable).

That's why many of us moved on. I gave up on Finale once MakeMusic gave up on all of us. If I need to tweak something, it's still there. But I would personally advise against using Finale for any new projects. I'm on my fourth new composition in Dorico since Sept and don't miss Finale very much at all (especially with all the bugs and old UX elements that will never be addressed; they weren't being addressed for the past few years as it was). Some people swear by Musescore. Others by Sibelius. I think for me, Dorico has been a good decision, warts and all (but probably fewer warts than Finale ever was). No need for plugins, I can mainly focus on composing, not trying to fight Finale's many glitches and bugs...

I can't speak for MakeMusic/Peaksware but my day job is Information Technology.

"Foreseeable future" likely means they will shut down the authorization as early as they feel like they can get away with it without as much pushback.

It is an internet-facing server, so if it is unmaintained (because no more developers are still on staff who know how it is programmed), it is likely a hacking risk. All it takes is a major vulnerability in some critical dependency and if you don't have a developer on staff who can patch that, it is at risk. If it did get hacked, it could be used as a springboard to hack into other systems at the same company which trust that server. 

If I was responsible for protecting the IT infrastructure of a company that ran this server, I would be constantly pressuring my bosses to get rid of it as soon as possible. A server openly running unmaintained code on the public Internet is just asking for trouble. Even if nothing happened, I would constantly be keeping an eye on it, for fear of what might happen. If I were responsible for their IT infrastructure, I would sleep better at night knowing the server was gone.

Completely agree. It would almost seem worth it to them to patch Concorde to disable the auth requirement but that requires development and testing and likely is t trivial. So disabling the server as soon as feasible after August seems tenable.

That would require development and testing and as mentioned in other posts/threads, could break something (hence the need for testing). It isn’t trivial and while possible, I suspect it’s very unlikely. Companies don’t usually act out of benevolence.

Thank you for all the responses, it gives me a better understanding of both sides.
As mentioned, an available version that didn't require authoristaion would be ideal, eg Adobe made older versions of Photoshop and Illustrator available for free download for some time (they may still be there for all I know but I haven't checked in a while).

Finale "phones home" only during initial installation. It never checks the license server once this is done. It doesn't have the ability.

If the license server goes dark tomorrow, our installations will remain intact. This is easy to test by disabling internet access to your computer and starting up Finale. New installations would not be possible without the, however.

There are other things that I have discovered about Finale licensing. Although I did not have to reverse-engineer anything, I would expect MM to remove that info should I post it here. Come September, I'll post on some of the other boards. If you want a clue, reread my first sentence.

Adobe made older versions of Photoshop and Illustrator available for free download for some time (they may still be there for all I know but I haven't checked in a while).

That must have been a long time ago. Those of us with valid licenses for older versions of Acrobat cannot re-install them when the drive is changed as the old license server does not allow a person to unregister an old activation so it will work with the new drive. Adobe Support says that they are powerless to correct this. That's just whack.

As mentioned, an available version that didn't require authoristaion would be ideal

Ain't gonna happen. Think about it. MM would have to update Finale for that to be possible—I just don't see MM doing that. Till then, we have to take them at their word. A future OS may break the installer or not. The license server will remain on "indefinitely".

Since the license manager cannot phone home after installation, installed copies will remain that way unless something else breaks.