In the FAQ they they mention the average Kagi user does 700 searches a month. Perhaps uncoincidentally, the $10/month plan includes exactly that many searches.
Without even considering the early adopter benefit, this pricing update for me is a nothing-burger.
https://blog.kagi.com/update-kagi-search-pricing#faq (Third question.)
The justification they give seems to be nonsense: "While we understand that this may be inconvenient for some users, it’s important to note that providing free trial accounts and supporting our team members’ salaries requires a delicate balance. "