They cant deduct the money from my other cards or wallets indirectly.
That's not really unexpected. They keep all those "worlds" separated.
But I had no warnings or anything. I find it a little strange.
Quite shame indeed, since it's in their best interest. Maybe you propose them add such notifications (if they don't think that far). Or did you stop all their notifications?! (asking just in case).
Gonna order a new USD card.
Please let us know how it went. Also read up: you need this only if you pay a lot in USD, else EUR/GBP cards should be cheaper.