I don't think it is a big deal, really. Modern combat aircraft never depend on their gun to do anything. Even 4th gen aircraft are nowadays expected to disengage if close-range combat (might still be BVR) is likely. Modern missiles are so effective that close range usually means both sides are getting a missile. An aircraft ending up in a situation where it was out of missiles, and couldn't disengage, and didn't get shot down is very unlikely.
The rationale behind the inclusion of the gun in the F-35 was that USAF thought an aircraft should be able to engage targets of opportunity on the ground. An F-35 spent its bombs and then saw a convoy? Strafe it. This is also why they switched to 25 mm from 20 mm.