I don't get why the article said they were testing ways to adjust the formation- it's not like Jungyeon left permanently, she's taking a much needed rest that honestly ALL the girls need. They left space for Mina EVERY time why? Because she didn't leave, she took time to rest and look after her mental and emotional well-being. And if anyone else ever needed to take time off, as we've sadly seen when there's been injuries in the group, they always do the same then as well.