You absolutely cannot be sued for selling a picture in the style of another artist. It may be debateable whether something is style or content. You can be sued

You absolutely cannot be sued for selling a picture in the style of another artist. It may be debateable whether something is style or content. You can be sued for selling a copy or a substantially similar work of art. You can make this happen with AI tools. It seems unlikely to me that someone could go after open AI if you use their tools to generate a copy right violation. But IANAL.