I actually do remember hearing about this somewhere, but even though I have their blog/updates in my RSS reader, they never officially mentioned this before this user brought it up—maybe in their Discord server? Thanks for pointing this out! I can imagine they really wanted to get away from Bing after the price surge, as that was only a signal of more to come. Duckduckgo seems to be paying for that with the massive increase in ads.
However, it is still disconcerting the degree to which Kagi is hugely reliant on Google. Doesn't change any of the positive aspects about Kagi, though.