Always make backups, but if everything fails you can always run an older Bitcoin Core version. A main goal of Bitcoin is to make it as backwards compatible as possible.
The only downfall with that is what might happen with VERY old wallets. You have to think in the possibility of DECADES.
Even now getting older software to run at times requires VMs and other things.
Some versions of the bitcoin client are difficult to find.
And so on.
Just something to think about.
-Dave
yeah I had this happen to me with 2 Eth coins.
While not btc these got stuck in an old Mac OS wallet due to the giant fix done early with eth . they were worth 6+6 dollars. when they got to 500 each 1000 total I really tried to free them and could not. So I am out 2 eth or 3500 usd at this moment.