I don't think it's that hard to determine. He has big companies involved in significant regulatory actions and oversight, he would stand to gain a lot by influencing things slightly in his favor. Sure, taken to absurdity everybody in government has a conflict of interest because they are alive on the same planet and have heir own views on things, but for the case of someone like Musk it's pretty clear.

Politicians and bureaucrats can and should consult with the people they govern of course. The "proper" way to do that would be via reasonably open and transparent process that is open to interested parties so competitors, customers, unions, scientists could have their say.

Again I'm fully aware this isn't how things actually work, so I'm not saying Musk is really doing anything outside the norm in American politics by buying a seat at the table. He's just being slightly more open about it than most of them.