There are probably close to a hundred posts in the thread last year from meteorologists and other interested observers commenting on the highly unusual transatlantic wind and weather patterns last year - it was considered a once-per-decade or even less frequent event. As a result there were some longer than usual segments that resulted in a higher than normal rate of fuel stops, mainly because it wasn't forecasted early enough to be able to manage passenger and cargo loads accordingly.
The other factor was the introduction of some unfamiliar segments (flights to IAD) which, in addition to being slightly longer were relatively immature in terms of UA's ability to forecast loads and exact aircraft performance.
Neither of those factors seem to exist to any meaningful degree this winter, so the planned fuel stop rate seems to be much closer to what it was 2+ years ago - i.e. effectively a non-issue.