Apparently, that is Coe's recommendation. As quoted in the LRC article, the organizing committee sent an email after the event stating the following:
At the VIP dinner last Friday, Lord Coe recommended that World Athletics permanently hold the World XC Championships here in Tallahassee. Last night, Amanda Heidecker, the co-chair of the Championships, confirmed Lord Coe’s recommendation, telling us he privately said he was being completely serious, because this committee was the best he’d ever worked with.
I believe Coe is serious, but I wonder if his words are meant to be a threat to other organizing committees while the bidding process is open to host the event in 2029 (link below). It seems to me that Coe is basically saying to other cities: "Give me what I want, or else I'll keep this event in Tallahassee."
I enjoyed my time in Tallahassee last weekend, but I wouldn't want every edition of the meet to be there. Part of what made the experience so fun was its novelty. I think it would get stale if the meet was there every time.
It's similar to Eugene. I love visiting Eugene to watch meets on occasion, but it's a pain to get to, and I don't want to go there for every national meet. I'd rather see those meets move around and have different places to visit.
I feel even more strongly about world meets. They shouldn't be in the same place every time. Other countries should get a chance to host.