Bitcoin Core, Electrum wallets have many wallet versions that were released in many years. You are fine if you store your bitcoin in old wallet versions.

If you have private key, your bitcoin is fine. Now and in future, if that wallet company is closed or the wallet software is abandoned for further development, you can move your bitcoin to a new wallet provides by another wallet software and company.

Not your keys, not your coins, that is to remind people that if they store their coins on exchange, they don't have private keys and if that exchange company closes or collapses or bankrupts, they will lose their coins.

With non custodial wallets and private keys, you are fine and don't have to care what happen with that wallet company.

Reminder: do not keep your money in online accounts