That’s completely false.
IRS doesn’t care who pays you for what, doesn’t care what conflict of interest you have or how elaborate your tax avoidance schemes are. Their only narrow interest is you paying what you are legally required to.
Trump lied time and time again about releasing his tax returns. You should not be giving him a pass on these lies and lack of standard transparency we expect from our Presidents.
Did you give DumBama a pass on the things he lied about? It's the Democrats that want his tax returns, and it could only help them in bashing him. Speaking of which, perhaps if they treated him a little better, he wouldn't be trying to piss them off as much. They began attacking him before he even set foot in the White House. WTF would he give them the satisfaction of showing his tax returns?
The IRS sifts through every deduction wealthy people have. If they found something suspicious about his returns, they would notify the proper authorities.