You're missing the point!
The point is:
Should we interfere with its trajectory before
2029 by any asteroid deflection technique or not?
Even if 2020 shows that there is a 100 percent
probability that Earth will be spared in 2029 and 2036,
does that give us the callous 'luxury' or right of letting
our grandchildren deal with the problem of future
threats from Alpophis?
I wouldn't dare let that dangerous burden fall [no pun intended]
on my grandchildren without ME (this generation) doing something practical with the technology available today to eliminate the
future threat of Alpophis..whether it threatens us 20 years...120 years...
or 1000 years in the future.
I wouldn't tolerate a politician or science-advisor who
expressed the view that 'it's not our problem today.'