By then, the proposed 130-metric-ton SLS may well be superseded by the Big Falcon Rocket under development by SpaceX or Blue Origin's proposed New Armstrong booster. In any case, comparing the Falcon Heavy to a rocket that won't exist for at least a decade and without many billions of dollars in public investment seems spurious. Boeing also makes no mention of the huge cost disparity between the two rockets.
There is one final interesting nugget on the Boeing website. The end of the SLS blurb invites readers to "Learn more about why the SLS is the right choice for NASA" by linking to a news story in the London Evening Standard. This is a conservative British tabloid owned by a Russian oligarch and former KGB agent, Alexander Lebedev.