I'd say no as well. The cost savings are likely not that much particularly when compared to the reroute and compensation costs for those on the cancelled flight.
The circumstances would have to be perfect as well. Since not all aircraft go out and back. (i.e. Squeezy could rotate an aircraft EDI-LPL-BRS-GVA-BRS-LGW-EDI) you can't cancel any single sector without affecting some of the others. Crewing also comes into it as a cancellation could result in crew being out of position and having to be transported by other means to their next flight. Same with the aircraft itself.
The EC thought this was a common practice by airlines, which is why Regulation 261 compensation is 'punitive'. However a study by outside consultants done a few years after it was implemented showed that the rate of cancellations changed not one bit. Airlines cancel their flights because they are unable to operate, not because it's not economical to.