Joseph Campbell mentioned archetypal imagery that are repeated which unifies cultures and represents various universal questions, curiosities, and ideas. The circle as well as imperfect, amorphous orbs exist even on cave dwellings proving that these symbols are deeply rooted in the human experience regardless or whether you're pre-historic or modern man/woman.
For me, it is also the simplistic, calming repetitive movement that circles and spirals inspire. For me, it definitely is therapeutic and is a great place to start to ignore the creative flow process. Have fun!

'Pre-art', such a matching name!

And yes, I'm doing that, too. Not circles, but I'm drawing stamp edges on my 10x15 cards, and I'm spoolknitting (that may become snail houses - thus a kind of circles) and knitting postable squares 'in case of'. Sometimes doodling or drawing snail mail snails on envelopes

Not therapeutic, I think, but to fill lost minutes. As for finishing mail art I need more time, those fragmented minutes (between tasks and other duties) are frustrating, but turn out to be ideal for creating pre-art :-) 

I call this Bringing It To The next Level. Which means cutting up bigger pieces, cutting strips and tiny elements, releasing pictures from their context. Gluing snippets together to form larger pieces, mini collages and abstract collages to cut up. Using the last stickers from sheets to put them in a tin of eyecatchers and mini-deco. Sorting papers by color and feel. Prepping postcards with paint. 

It is nice to do when I creatively clean up and put things in more inspiring arrangements. When I know what to do with the elements I feel less obstructed by fuzzy cutting or searching for the right element to lift the whole. 

I won't call it therapeutic, I would call it prepping to make the best use of the creative flow when it's finally there again. It also gets my brain in the mood to think of all the wonderful things to do with these materials.