Having seen clips of old BBC & Sky Channel Idents on YT, i was wondering if there is any Ai video software that could create a custom Ident.

OpenAI, Google and Facebook have their own AI video creation tools under development, so you should keep your eyes peeled.

At work I've used Aurora 3D to make idents fot internal project, and it was easy to recreate the BBC mirror globe idents from the 70s-85 with it as well. It has a lot of samples as well for people to try out: https://www.presentation-3d.com/downloads.html

And DALL·E 3 (accessible via ChatGPT 4, and Bing [not recommend]) gets the spirit of static images of TV idents. I tried loads of combinations, with some brief and convoluted prompts for the likes of Tyne Tees and BBC1 globes. The results were not great. Hopefully someday a reliable DAN (Do Anything Now) prompt will appear for ChatGPT 4 (I have pushed it at times with interesting results).

If you like watching old TV Idents and Intro then I recommend this website - https://www.tvark.org/