Yes, you don't have to be in stealth mode in MJ to generate images for sale but you must have a paid account (I believe) to be able to commercialize them. Look under 'Your Rights' in MJ ToS: https://docs.midjourney.com/docs/terms-of-service

In a nutshell, I asked ChatGPT-4 with Bing browse to read that page and answer your question and this is the answer (so this is not legal advice but a demonstration of how the LLM can help sift through the legal jargon):

"Yes, you can sell images created in Midjourney, provided you adhere to their terms. If you're not a paid member, your assets are licensed under the Creative Commons Noncommercial 4.0 Attribution International License, which restricts commercial use. However, if you're a paid member or your company has a "Pro" or "Mega" membership, you own the assets you create and can sell them."