My experience: I have a MIM PJ to which I added EMG PJX pups and controls, Hipshot bridge, after market pick guard and a Squire Jazz lined fretless neck. Also had a WD fretless Jazz neck on it for a while. All fit with out issue.
Then came a 2018 MIM Jazz body that I bought loaded. I put an after market pick guard on it and both of the above necks. It currently has the WD neck on it. All with out issue. I have an Audere 3 band preamp set up that will be dropped in soon.
Next came a 2016 MIM Jazz Body that I bought with nothing but a fender high mass bridge installed. I tried two different after market pick guards and they both fit. I bought a Fender MIJ fretless neck for it but it would not fit into the neck pocket. Next I bought a Fender Squire VM neck that fit right into the pocket. Finally I purchased a Warmoth fretless neck but it wouldn't fit into the neck pocket either.
Not sure why the issues with the 2016 body. I am unable to verify the body serial number MO4600915 either.
So you just never know...
Then came a 2018 MIM Jazz body that I bought loaded. I put an after market pick guard on it and both of the above necks. It currently has the WD neck on it. All with out issue. I have an Audere 3 band preamp set up that will be dropped in soon.
Next came a 2016 MIM Jazz Body that I bought with nothing but a fender high mass bridge installed. I tried two different after market pick guards and they both fit. I bought a Fender MIJ fretless neck for it but it would not fit into the neck pocket. Next I bought a Fender Squire VM neck that fit right into the pocket. Finally I purchased a Warmoth fretless neck but it wouldn't fit into the neck pocket either.
Not sure why the issues with the 2016 body. I am unable to verify the body serial number MO4600915 either.
So you just never know...