first off yes it will fix the issue if it is not hardware related to anything else in the phone. to answer the question of if it will happen again. that will depend on what is causing the boot loop, majority of the time boot loops can be fixed with out changing the whole mobo or motherboard. i personally have not had any boot loop issue with my unlocked att lg g4 and it is my daily user phone. can you give us more info?
1. any damage or drops?
2. any attempts at rooting or was it rooted?
3. any software mods?
4. any recent changes in temperature of the phone or any kind of changes, cases or battery swap, etc etc?