They should definitely consider an extra <select> field for the generic one, with the names of the issue types on then. And one pre-selected when going from a specific one.

How to change from bug issue template to normal issue template or for feature request? Changing the URL manually is not going to cut it, and the interface looks like the generic one for issues so users would expect going back to issues => new is going to be the same.

IMHO this could have been so good and useful, but they messed up the implementation details...

Note/Edit: I didn't look at Gitlab's implementation before comenting this, but now that I saw it that is exactly what I imagined/described here!