I don't think that's true, because it appears to me that the upswing in new TUI programs predates Claude Code's takeoff.
This is the case. The advent of libraries like Rich and others certainly helped, along with the trend of Rust TUIs for system programming/lack of good GUI options.
Claude Code uses Ink, a react library in javascript for UI. The upswing is probably stuff like this making it super easy to write a TUI.
rust community likes tui ever since Ratatui and some other packages are making it easier than for example ncurses or notcurses etc. - i think Ratatui package is one big propellor for tui use and creation nowadays from slightly before claude code etc.