Don't be afraid of editors. The creator community likes to freak out about them sometimes but by and large they are there to focus, improve, and keep consistency within your story. Their whole job is to give you the feedback to tell your story better according to your vision. They are not there to demean your story, they are there to enhance it. If they are hiring you on, they LIKE your work, and opposing its core themes would only work against them.
That doesn't mean there aren't bad editors, or ones that only have the company's interests at heart. But I wouldn't go in assuming the worst case scenario! If you ever enter into contract negotiations, comb through that contract, hire a lawyer to comb through it too, and ask about anything that worries you. Ask about their process and what their editor does. Often times, yes, the publisher/editor have ultimate final say on what you're producing, but like... ideally, you're just collaborating with them to make you both happy.
I would also recommend having some emotional distance from your ideas so you're not devastated if it doesn't go exactly how you want. Maybe don't enter a contract using a story that's really close to your heart--use one that's fun, short, and flexible. I probably won't try to get my current webcomic published, for example, but I have like 3 other stories farting around in my head that I'd love to do if someone wants to throw money at me!
And real quick, I wanted to addess this:
This is normal for literally every production pipeline I have worked in. This isn't weird or something to be up in arms over. This isn't a, "God they're micromanaging me and just not letting me work!!" situation, it's "We need to make sure this is going in the direction we agreed on while it's still in the early stages so changes are easy to make".