Instagram has a limit of 60 unfollows/follows per hour, so no, they won’t block you permanently, but if you surpass that limit they will stop your ability to follow/unfollow for one hour, and then you’re back to normal. You should never be totally blocked though, only the temporary block.
What happens after 10k followers on Instagram?
Once you have 10k followers, Instagram will make it easier for you to get people to your website via Stories with the swipe up to link feature. Swipe up is the only way to get a direct link from your Instagram to your other web properties. And, it’s available in STORIES, if you have 10k followers.