Many of the loading spinners on Chase bank's rewards portal have a "Pause Animation" button below them. Is there a reason to include this below animations?
The one reason I can think of (which only applies to mobile devices) is that it can save processing power, and thus, battery power.
When I turn my phone onto Battery Saving mode all animations stop being processed. This in turn saves my battery juice for a little longer by not running those processes.
Since your example is on a desktop/laptop or otherwise, I would guess it might be due to incompatibility in some browsers... maybe it looks weird in IE?
Otherwise, as @LisaTweedie said, it's over-engineering.