Qualcomm has an official contract with Samsung at the moment, which was visible at the moment of launch of the Samsung Galaxy S8. Samsung demanded that when company will launch its new device Galaxy S8 must be the only phone on the market with the Qualcomm Snapdragon 835. That's why LG wasn't able to use this processor during production of the LG G6. As it turns out, in the future situation between these companies may be different.
Qualcomm has released an official statement announcing that company plans to work with LG to develop its new Qualcomm Snapdragon 845 processor. This information shows that LG G7 probably will debut on the market with the latest Qualcomm's processor. LG so far hasn't addressed this issue and firm focuses on the launch of the LG V30.