Great question — answering as the UphillTech team:
As a huge The West Wing fan, to me the flash-forward was a pleasant surprise from the regular chronological (1) story telling, and I did not experience it as being a spoiler. In fact, as trigger to keep watching, quite the opposite: At the end of the sixth season, it is unclear if Toby will be caught for leaking classified information, so Bartlet to Toby saying "Glad you could make it." could mean anything from Toby being free and working abroad to Toby gotten a temporary release from prison. For six seasons long already, we are in anticipation of a growing relationship between CJ and Danny. Seeing them together in that scene answers that indeed, but it was not within expectancy anymore...
Full answer by NGLN: https://movies.stackexchange.com/a/9427 (CC BY-SA 3.0).
Need it done for your business? UphillTech.