its going to beat 3ds but beating xbox is not a sure thing, especially with how nintendo consoles usually lose momentum much faster.
Nintendo consoles lose momentum faster than Xbox based on what exactly?
Peak-2004 (3rd year)
Peak-2011 (6th year)
What does a normal cycle for Xbox look like?
Here are the Nintendo consoles since 2001
Peak-2003 (3rd year)
Peak-2003 (2nd year)
Peak-2008 or 2009 (4th/5th year)
Peak-2008 (2nd year)
Peak-2011 (1st year)
Peak-2014 (2nd year)
Based on that when does a normal Xbox console lose momentum and when does a normal Nintendo console lose momentum?
If Switch was just a home console than you could make a good guess but its also a handheld which are not nearly as consistent.
Saying Nintendo consoles normally lose momentum faster than Xbox consoles is based on absolutely nothing.
When the herd loses its way, the shepard must kill the bull that leads them astray.