These are bugs, but I'm not sure they are what you think they are. I would be worried if TextSecure indicates a message is going to be sent securely, but it is sent insecurely. This bug, however, is an edge case where TextSecure indicates that it is going to send a message insecurely, and that's what it does.

It's also true that until recently we didn't have an encrypted group chat protocol, but at no point in the past did TextSecure ever indicate that group chat was encrypted. Just the opposite.

It's important to realize that TextSecure is simultaneously a standard unencrypted SMS app as well as an encrypted chat app.