Is it possible that money could be lost if you try to withdraw to a bc1 address but the service doesn't support it?
I'm struggling to envisage a situation where it would be.
Either the service would broadcast the transaction, in which case you would receive the coins in your address, or they wouldn't, in which case the coins would never leave the service. It would be possible, I suppose, that a particularly poorly set up service could debit the coins from your account with them, but then fail to make the transaction because their system didn't recognise a bc1 address. Since the coins never actually left their system in that case, and it was only the balance of your account with them which was updated, then they would be able to rectify this via contacting their support service.
The few times in the past I tried to withdraw to a bc1 address which a service didn't support, I was simply met with an "Invalid address" error or similar whenever I entered my address. I was never able to actually submit a withdrawal request or get anywhere near creating a transaction.
