10/11/16 12:46pm ET: United just provided the following statement about this change:
The new MileagePlus redemption award changes have been designed to make multi-city searches easier, give our customers greater flexibility, offer the Excursionist Perk, and provide efficient options that meet their travel needs. Selecting the multi-city option where United offers nonstop service will break up the search into two separate awards. We believe our multi-city pricing is consistent with the industry. Additionally, our customers have greater flexibility when booking multi-city travel. United.com offers ways to optimize searches – for example, you can select preferred connection cities, specific airports, etc.