One way to do it would be to use the freestyle method and in the view layer properties tick the «as render pass» box under the freestyle options. Then you can animate and fade in and out the solid and wireframe/freestyle passes in the compositor with the set alpha node.
I know this is jumping through the compositor hoop, but it is not too bad.
Edit: mmm I can not seem to work out how to fade the freestyle pass with set alpha so maybe not so easy.
There must be some way of doing this with the compositor If anyone has any ideas?
Well this seems to work, a few more hoops!
I had to separate the background (film transparent), I used a simple yellow colour for background.
The node setup for compositor was this:
Maybe someone has a more simple idea!