Not completely. A large part of the performance problems of an interference tube microphone (aka "shotgun") is about more than just the amount of reverb -- it's also about how quickly that reverb shows up at the mic. That is, the closer to a reflective surface you are, the more likely the sound entering the tube through the slots will interfere with the direct sound coming down the tube that you want to keep.

If the distance to the reflective surface(s) is great enough, an interference tube mic works just fine, indoors or out. Which is why dialog recordists can get away with using them on indoor soundstages where actual reflective surfaces are reasonably far away.

All that said, interference tube mics are nearly always going to sound somewhat colored off axis. It's just how they work. This is perhaps why when non-dialog people want more "reach" and less pickup from off-axis, they use hypercardioids or supercardioids instead.