I'm seeing a problem with the Azure CLI extension on Insiders today as well that may be related.
When I try to execute any command (using cmd+' or ctrl+') I get this error:
running the contributed command:'ms-azurecli.runLineInTerminal' failed
Here is the command being executed that appears to be failing:
return commands.executeCommand('workbench.action.terminal.runSelectedText', editor);
And the location...
https://github.com/Microsoft/vscode-azurecli/blob/0f59292f07f1b449a8e86f9708fff61d090e569d/src/extension.ts#L141
Perhaps related to microsoft/vscode#27939