There are many things that can happen to a non-profit that can change the way they provide software or a service. Apart from a sale being possible (albeit with regulator approval), a non-profit could split (see MozillaCorp), or simply act against its own stated interest due to internal politics (see PIR).
Or the change could be smaller such as the non-profit changing focus and transferring one of it's products to another entity. e.g. Signal could hypothetically pivot to focus on crypto lib dev/maintenance and transfer the messaging service maintenance to another org.
Brian Acton, WhatsApp co-founder, one who left Facebook post-acquisition, infused 50M USD into Signal. And, Signal is community-supported through donations. I hope that Signal remains here for a long time.
It is strange he moved from seeing a centralized messenger project he founded be morphed into a monster, only to double down and invest in yet another privacy hostile centralized messaging system hoping for a different result.
Anything not decentralized is going to get abused eventually.
The US government could seize the client signing keys, release s backdoored client, and dump the SGX keys and gag order everything in the name of national security. We have seen similar play out in China. Even the mighty Apple gave up HSM keys and caved to CCP censorship demands. It is only a matter of time.
I fear they are well meaning but woefully naive.
We need censorship resistant standard protocols anyone can implement and help host so there is no SPOF.
Moxie doesn't care about sellout money. As I understand it he wants to run signal as a lifestyle business, and he has private donors keeping everything afloat. I'm not sure if it'll stay independant if Moxie ever leaves, but hopefully there's a stable org structure. Source: The JRE podcast he did a couple months back.
Also if they ever sell out, the server & clients are completely opensource. It wouldn't take much for someone else to fork the whole thing and run a competing service if we ever need to.
Or the change could be smaller such as the non-profit changing focus and transferring one of it's products to another entity. e.g. Signal could hypothetically pivot to focus on crypto lib dev/maintenance and transfer the messaging service maintenance to another org.